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|
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HTML Working Group T. Berners-Lee |
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INTERNET-DRAFT MIT/W3C |
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<draft-ietf-html-spec-03.txt> D. Connolly |
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Expires: In six months May 31, 1995 |
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|
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|
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Hypertext Markup Language - 2.0 |
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|
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|
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CONTENTS |
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|
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|
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1. Introduction |
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2. HTML as an Application of SGML |
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3. HTML as an Internet Media Type |
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4. Document Structure |
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5. Character, Words, and Paragraphs |
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6. Hyperlinks |
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7. Forms |
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8. HTML Public Text |
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9. Glossary |
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10. Bibliography |
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11. Appendices |
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12. Acknowledgments |
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|
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|
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|
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Status of this Memo |
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|
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This document is an Internet-Draft. Internet-Drafts are working |
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documents of the Internet Engineering Task Force (IETF), its areas, |
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and its working groups. Note that other groups may also distribute |
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working documents as Internet-Drafts. |
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|
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Internet-Drafts are draft documents valid for a maximum of six months |
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and may be updated, replaced, or obsoleted by other documents at any |
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time. It is inappropriate to use Internet-Drafts as reference material |
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or to cite them other than as ``work in progress.'' |
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|
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To learn the current status of any Internet-Draft, please check the |
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1id-abstracts.txt listing contained in the Internet-Drafts Shadow |
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Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), |
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munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or |
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ftp.isi.edu (US West Coast). |
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|
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Distribution of this document is unlimited. Please send comments to |
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the HTML working group (HTML-WG) of the Internet Engineering Task |
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Force (IETF) at <html-wg@oclc.org>. Discussions of the group are |
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archived at <URL:http://www.acl.lanl.gov/HTML_WG/archives.html>. |
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|
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In this draft, the first three sections are considered essentially |
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finished. Sections 4 and 5 have been significantly revised and are |
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open to comments, though I'm fairly happy with those parts. Section 6 |
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is somewhat new: it collects all information about hyperlinking into |
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one place. Sections 7 (forms elements) has also been revised, and |
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there are a few points I'm not sure on. The glossary (section 8) has |
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also been tweaked. Section 8 ``public text'' has been stable for some |
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time, but as it's critical, I'd appreciate a careful review just the |
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same. |
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|
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|
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ABSTRACT |
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|
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The Hypertext Markup Language (HTML) is a simple markup |
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language used to create hypertext documents that are |
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platform independent. HTML documents are SGML documents with |
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generic semantics that are appropriate for representing |
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information from a wide range of domains. HTML markup can |
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represent hypertext news, mail, documentation, and |
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hypermedia; menus of options; database query results; simple |
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structured documents with in-lined graphics; and hypertext |
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views of existing bodies of information. |
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|
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HTML has been in use by the World Wide Web (WWW) global |
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information initiative since 1990. This specification |
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roughly corresponds to the capabilities of HTML in common |
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use prior to June 1994. HTML is an application of ISO |
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Standard 8879:1986 Information Processing Text and Office |
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Systems; Standard Generalized Markup Language (SGML). |
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|
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The `"text/html; version=2.0"' Internet Media Type (RFC |
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1590) and MIME Content Type (RFC 1521) is defined by this |
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specification. |
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|
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|
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1. Introduction |
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|
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The HyperText Markup Language (HTML) is a simple data format |
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used to create hypertext documents that are portable from |
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one platform to another. HTML documents are SGML documents |
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with generic semantics that are appropriate for representing |
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information from a wide range of domains. |
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|
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|
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1.1. Scope |
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|
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HTML has been in use by the World-Wide Web (WWW) global |
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information initiative since 1990. This specification |
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corresponds to the capabilities of HTML in common use prior |
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to June 1994 and referred to as ``HTML 2.0''. |
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|
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HTML is an application of ISO Standard 8879:1986 |
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_Information Processing Text and Office Systems; Standard |
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Generalized Markup Language_ (SGML). The HTML Document Type |
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Definition (DTD) is a formal definition of the HTML syntax |
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in terms of SGML. |
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|
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This specification also defines HTML as an Internet Media |
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Type[IMEDIA] and MIME Content Type[MIME] called `text/html', |
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or `text/html; version=2.0'. As such, it defines the |
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semantics of the HTML syntax and how that syntax should be |
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interpreted by user agents. |
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|
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|
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1.2. Conformance |
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|
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This specification governs the syntax of HTML documents and |
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the behaviour of HTML user agents. |
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|
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|
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1.2.1. Documents |
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|
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A document is a conforming HTML document only if: |
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|
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* It is a conforming SGML document, and it conforms to |
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the HTML DTD (see 8.1, "HTML DTD"). |
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|
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NOTE - There are a number of syntactic idioms that are |
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not supported or are supported inconsistently in some |
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historical user agent implementations. These idioms are |
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called out in notes like this throughout this |
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specification. |
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HTML documents should not contain these idioms, at |
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least until such time as support for them is widely |
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deployed. |
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|
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* It conforms to the application conventions in this |
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specification. For example, the value of the HREF |
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attribute of the <A> element must conform to the URI |
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syntax. |
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|
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* Its document character set includes ANSI/ISO 8859-1 |
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and agrees with ISO/IEC 10646-1; that is, each code |
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position listed in 11.1, "The ANSI/ISO 8859-1 Coded |
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Character Set" is included, and each code position in |
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the document character set is mapped to the same |
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character as ISO10646 designates for that code |
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position. |
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|
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NOTE - The document character set is somewhat |
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independent of the character encoding scheme used to |
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represent a document. For example, the ISO-2022-JP |
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character encoding scheme can be used for HTML |
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documents, since its repertoire is a subset of the |
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ISO10646 repertoire. The critical distinction is that |
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numeric character references agree with ISO10646 |
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regardless of how the document is encoded. |
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|
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The HTML DTD defines a standard HTML document type and |
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several variations, based on feature test entities: |
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|
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|
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HTML.Recommended |
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Certain features of the language are necessary for |
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compatibility with widespread usage, but they may |
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compromise the structural integrity of a document. |
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This feature test entity enables a more |
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prescriptive document type definition that |
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eliminates those features. |
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|
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For example, in order to preserve the structure of |
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a document, an editing user agent may translate |
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HTML documents to the recommended subset, or it |
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may require that the documents be in the |
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recommended subset for import. |
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|
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HTML.Deprecated |
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Certain features of the language are necessary for |
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compatibility with earlier versions of the |
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specification, but they tend to be used and |
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implemented inconsistently, and their use is |
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deprecated. This feature test entity enables a |
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document type definition that eliminates these |
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features. |
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|
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Documents generated by tranlation software or |
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editing software should not contain these idioms. |
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|
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|
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1.2.2. User Agents |
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|
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An HTML user agent conforms to this specification if: |
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|
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* It parses the characters of an HTML document into |
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data characters and markup according to [SGML]. |
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|
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NOTE - In the interest of robustness and extensibility, |
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there are a number of widely deployed conventions for |
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handling non-conforming documents. See 3.2.1, |
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"Undeclared Markup Error Handling" for details. |
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|
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* It supports the `ISO-8859-1' character encoding |
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scheme and processes each character in the ISO Latin |
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Alphabet No. 1 as specified in 5.1, "The ISO Latin 1 |
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Character Repertoire". |
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|
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NOTE - To support non-western writing systems, HTML |
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user agents should support ISO-10646-UCS-2 or similar |
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character encoding schemes and as much of the character |
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repertoire of ISO10646 as is practical. |
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|
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* It behaves identically for documents whose parsed |
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token sequences are identical. |
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For example, comments and the whitespace in tags |
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disappear during tokenization, and hence they do not |
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influence the behaviour of conforming user agents. |
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|
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* It allows the user to traverse (or at least attempt |
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to traverse, resources permitting) all hyperlinks in an |
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HTML document. |
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|
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* It allows the user to express all form field values |
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specified in an HTML document and to (attempt to) |
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submit the values as requests to information services. |
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|
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|
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2. HTML as an Application of SGML |
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|
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HTML is an application of ISO 8879:1986 -- Standard |
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Generalized Markup Language (SGML). SGML is a system for |
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defining structured document types and markup languages to |
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represent instances of those document types[SGML]. The |
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public text -- DTD and SGML declaration -- of the HTML |
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document type definition are provided in 8, "HTML Public |
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Text". |
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|
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The term _HTML_ refers to both the document type defined |
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here and the markup language for representing instances of |
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this document type. |
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|
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|
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2.1. SGML Documents |
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|
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An HTML document is an SGML document; that is, a sequence of |
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characters organized physically into a set of entities, and |
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logically as a hierarchy of elements. |
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|
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The first production of the SGML grammar separates an SGML |
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document into three parts: an SGML declaration, a prologue, |
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and an instance. For the purposes of this specification, the |
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prologue is a DTD. This DTD describes another grammar: the |
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start symbol is given in the doctype declaration, the |
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terminals are data characters and tags, and the productions |
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are determined by the element declarations. The instance |
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must conform to the DTD, that is, it must be in the language |
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defined by this grammar. |
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|
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The SGML declaration determines the lexicon of the grammar. |
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It specifies the document character set, which determines a |
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character repertoire that contains all characters that occur |
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in all text entities in the document, and the code positions |
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associated with those characters. |
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|
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The SGML declaration also specifies the syntax-reference |
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character set of the document, and a few other parameters |
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that bind the abstract syntax of SGML to a concrete syntax. |
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This concrete syntax determines how the sequence of |
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characters of the document is mapped to a sequence of |
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terminals in the grammar of the prologue. |
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|
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For example, consider the following document: |
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|
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<!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN"> |
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<title>Parsing Example</title> |
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<p>Some text. <em>*wow*</em></p> |
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|
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An HTML user agent should use the SGML declaration that is |
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given in 8.2, "SGML Declaration for HTML". According to its |
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document character set, `*' refers to an asterisk |
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character. |
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|
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The instance above is regarded as the following sequence of |
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terminals: |
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|
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1. TITLE start-tag |
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|
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2. data characters: ``Parsing Example'' |
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|
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3. TITLE end-tag |
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|
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4. P start-tag |
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|
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5. data characters ``Some text. '' |
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|
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6. EM start-tag |
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|
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7. ``*wow*'' |
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|
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8. EM end-tag |
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|
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9. P end-tag |
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|
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The start symbol of the DTD grammar is HTML, and the |
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productions are given in the public text identified by |
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`-//IETF//DTD HTML 2.0//EN' (8.1, "HTML DTD"). Hence the |
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terminals above parse as: |
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|
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HTML |
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| |
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\-HEAD |
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| | |
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| \-TITLE |
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| | |
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| \-<TITLE> |
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| | |
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| \-"Parsing Example" |
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| | |
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| \-</TITLE> |
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| |
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\-BODY |
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| |
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\-P |
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| |
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\-<P> |
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| |
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\-"Some text. " |
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| |
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\-EM |
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| | |
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| \-<EM> |
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| | |
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| \-"*wow*" |
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| | |
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| \-</EM> |
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| |
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\-</P> |
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|
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|
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2.2. HTML Lexical Syntax |
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|
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SGML specifies an abstract syntax and a reference concrete |
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syntax. Aside from certain quantities and capacities (e.g. |
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the limit on the length of a name), all HTML documents use |
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the reference concrete syntax. In particular, all markup |
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characters are in the repertoire of ISO 646 IRV. Data |
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characters are drawn from the document character set (see 5, |
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"Character, Words, and Paragraphs"). |
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|
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A complete discussion of SGML parsing, e.g. the mapping of a |
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sequence of characters to a sequence of tags and data, is |
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left to the SGML standard[SGML]. This section is only a |
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summary. |
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|
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|
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2.2.1. Data Characters |
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|
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Any sequence of characters that do not constitute markup |
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(see 9.6 ``Delimiter Recognition'' of [SGML]) are mapped |
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directly to strings of data characters. Some markup also |
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maps to data character strings. Numeric character references |
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also map to single-character strings, via the document |
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character set. Each reference to one of the general entities |
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defined in the HTML DTD also maps to a single-character |
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string. |
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|
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For example, |
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|
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abc<def => "abc","<","def" |
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abc<def => "abc","<","def" |
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|
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Note that the terminating semicolon is only necessary when |
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the character following the reference would otherwise be |
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recognized as markup: |
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|
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abc < def => "abc ","<"," def" |
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abc < def => "abc ","<"," def" |
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|
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And note that an ampersand is only recognized as markup when |
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it is followed by a letter or digit: |
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|
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abc & lt def => "abc & lt def" |
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abc & 60 def => "abc & 60 def" |
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|
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A useful technique for translating plain text to HTML is to |
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replace each '<', '&', and '>' by an entity reference or |
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numeric character reference as follows: |
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|
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ENTITY NUMERIC |
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CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION |
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& & & Ampersand |
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< < < Less than |
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> > > Greater than |
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|
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NOTE - There are SGML mechanisms, CDATA and RCDATA, to |
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allow most `<', `>', and `&' characters to be entered |
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without the use of entity references. Because these |
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features tend to be used and implemented |
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inconsistently, and because they conflict with |
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techniques for reducing HTML to 7 bit ASCII for |
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transport, they are not used in this version of the |
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HTML DTD. |
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|
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|
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2.2.2. Tags |
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|
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Tags delimit elements such as headings, paragraphs, lists, |
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character highlighting, and links. Most HTML elements are |
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identified in a document as a start-tag, which gives the |
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element name and attributes, followed by the content, |
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followed by the end tag. Start-tags are delimited by `<' and |
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`>'; end tags are delimited by `</' and `>'. An example is: |
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|
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<H1>This is a Heading</H1> |
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|
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Some elements only have a start-tag without an end-tag. For |
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example, to create a line break, you use the `<BR>' tag. |
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Additionally, the end tags of some other elements, such as |
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Paragraph (`</P>'), List Item (`</LI>'), Definition Term |
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(`</DT>'), and Definition Description (`<DD>') elements, may |
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be omitted. |
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|
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The content of an element is a sequence of data character |
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strings and nested elements. Some elements, such as anchors, |
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cannot be nested. Anchors and character highlighting may be |
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put inside other constructs. See the HTML DTD, 8.1, "HTML |
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DTD" for full details. |
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|
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NOTE - The SGML declaration for HTML specifies SHORTTAG |
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YES, which means that there are other valid syntaxes |
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for tags, such as NET tags, `<EM/.../'; empty start |
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tags, `<>'; and empty end-tags, `</>'. Until support |
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for these idioms is widely deployed, their use is |
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strongly discouraged. |
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|
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|
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2.2.3. Names |
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|
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A name consists of a letter followed by up to 71 letters, |
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digits, periods, or hyphens. Element names are not case |
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sensitive, but entity names are. For example, |
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`<BLOCKQUOTE>', `<BlockQuote>', and `<blockquote>' are |
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equivalent, whereas `&' is different from `&'. |
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|
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In a start-tag, the element name must immediately follow the |
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tag open delimiter `<'. |
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|
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|
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2.2.4. Attributes |
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|
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In a start-tag, white space and attributes are allowed |
452 |
between the element name and the closing delimiter. An |
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attribute typically consists of an attribute name, an equal |
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sign, and a value, though some attributes may be just a |
455 |
value. White space is allowed around the equal sign. |
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|
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The value of the attribute may be either: |
458 |
|
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* A string literal, delimited by single quotes or |
460 |
double quotes and not containing any occurrences of the |
461 |
delimiting character. |
462 |
|
463 |
NOTE - Some historical implementations consider any |
464 |
occurrence of the `>' character to signal the end of a |
465 |
tag. For compatibility with such implementations, when |
466 |
`>' appears in an attribute value, it should be |
467 |
represented with a numeric character reference. For |
468 |
example, `<IMG SRC="eq1.jpg" alt="a>b">' should be |
469 |
written `<IMG SRC="eq1.jpg" alt="a>b">' or `<IMG |
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SRC="eq1.jpg" alt="a>b">'. |
471 |
|
472 |
* A name token (a sequence of letters, digits, periods, |
473 |
or hyphens). |
474 |
|
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NOTE - Some historical implementations allow any |
476 |
character except space or `>' in a name token. |
477 |
|
478 |
In this example, <img> is the element name, src is the |
479 |
attribute name, and `http://host/dir/file.gif' is the |
480 |
attribute value: |
481 |
|
482 |
<img src='http://host/dir/file.gif'> |
483 |
|
484 |
A useful technique for computing an attribute value literal |
485 |
for a given string is to replace each quote and space |
486 |
character by an entity reference or numeric character |
487 |
reference as follows: |
488 |
|
489 |
ENTITY NUMERIC |
490 |
CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION |
491 |
TAB 	 Tab |
492 |
LF Line Feed |
493 |
CR Carriage Return |
494 |
  Space |
495 |
" " " Quotation mark |
496 |
& & & Ampersand |
497 |
|
498 |
For example: |
499 |
|
500 |
<IMG SRC="image.jpg" alt="First "real" example"> |
501 |
|
502 |
Note that the SGML declaration in section 13.3 limits the |
503 |
length of an attribute value to 1024 characters. |
504 |
|
505 |
Attributes such as ISMAP and COMPACT may be written using a |
506 |
minimized syntax. The markup: |
507 |
|
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<UL COMPACT="compact"> |
509 |
|
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can be written using a minimized syntax: |
511 |
|
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<UL COMPACT> |
513 |
|
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NOTE - Some historical implementations only understand |
515 |
the minimized syntax. |
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|
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|
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2.2.5. Comments |
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|
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To include comments in an HTML document, use a comment |
521 |
declaration. A comment declaration consists of `<!' followed |
522 |
by zero or more comments followed by `>'. Each comment |
523 |
starts with `--' and includes all text up to and including |
524 |
the next occurrence of `--'. In a comment declaration, white |
525 |
space is allowed after each comment, but not before the |
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first comment. The entire comment declaration is ignored. |
527 |
|
528 |
NOTE - Some historical HTML implementations incorrectly |
529 |
consider any `>' character to be the termination of a |
530 |
comment. |
531 |
|
532 |
For example: |
533 |
|
534 |
<HEAD> |
535 |
<TITLE>HTML Comment Example</TITLE> |
536 |
<!-- Id: html-sgml.sgm,v 1.5 1995/05/26 21:29:50 connolly Exp --> |
537 |
<!-- another -- -- comment --> |
538 |
<!> |
539 |
</HEAD> |
540 |
<BODY> |
541 |
<p> <!- not a comment, just regular old data characters -> |
542 |
|
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|
544 |
2.2.6. Example HTML Document |
545 |
|
546 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> |
547 |
<HTML> |
548 |
<!-- Here's a good place to put a comment. --> |
549 |
<HEAD> |
550 |
<TITLE>Structural Example</TITLE> |
551 |
</HEAD><BODY> |
552 |
<H1>First Header</H1> |
553 |
<P>This is a paragraph in the example HTML file. Keep in mind |
554 |
that the title does not appear in the document text, but that |
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the header (defined by H1) does.</P> |
556 |
<OL> |
557 |
<LI>First item in an ordered list. |
558 |
<LI>Second item in an ordered list. |
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<UL COMPACT> |
560 |
<LI> Note that lists can be nested; |
561 |
<LI> Whitespace may be used to assist in reading the |
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HTML source. |
563 |
</UL> |
564 |
<LI>Third item in an ordered list. |
565 |
</OL> |
566 |
<P>This is an additional paragraph. Technically, end tags are |
567 |
not required for paragraphs, although they are allowed. You can |
568 |
include character highlighting in a paragraph. <EM>This sentence |
569 |
of the paragraph is emphasized.</EM> Note that the </P> |
570 |
end tag has been omitted. |
571 |
<P> |
572 |
<IMG SRC ="triangle.xbm" alt="Warning: "> |
573 |
Be sure to read these <b>bold instructions</b>. |
574 |
</BODY></HTML> |
575 |
|
576 |
|
577 |
3. HTML as an Internet Media Type |
578 |
|
579 |
An HTML user agent allows users to interact with resources |
580 |
which have HTML representations. At a minimum, it must allow |
581 |
users to examine and navigate the content of HTML level 1 |
582 |
documents. HTML user agents should be able to preserve all |
583 |
formatting distinctions represented in an HTML document, and |
584 |
be able to simultaneously present resources referred to by |
585 |
IMG elements (they may ignore some formatting distinctions |
586 |
or IMG resources at the request of the user). Conforming |
587 |
HTML user agents should support form entry and submission. |
588 |
|
589 |
|
590 |
3.1. text/html media type |
591 |
|
592 |
This specification defines the Internet Media Type[IMEDIA] |
593 |
(formerly referred to as the Content Type[MIME]) called |
594 |
`text/html'. The following is to be registered with [IANA]. |
595 |
|
596 |
Media Type name |
597 |
text |
598 |
|
599 |
Media subtype |
600 |
name |
601 |
html |
602 |
|
603 |
Required |
604 |
parameters |
605 |
none |
606 |
|
607 |
Optional |
608 |
parameters |
609 |
level, charset |
610 |
|
611 |
Encoding |
612 |
considerations |
613 |
any encoding is allowed |
614 |
|
615 |
Security |
616 |
considerations |
617 |
see 3.3, "Security Considerations" |
618 |
|
619 |
The optional parameters are defined as follows: |
620 |
|
621 |
Level |
622 |
The level parameter specifies the feature set used |
623 |
in the document. The level is an integer number, |
624 |
implying that any features of same or lower level |
625 |
may be present in the document. Level 1 is all |
626 |
features defined in this specification except |
627 |
those that require the <FORM> element. Level 2 |
628 |
includes form processing. Level 2 is the default. |
629 |
|
630 |
Charset |
631 |
The charset parameter (as defined in section 7.1.1 |
632 |
of RFC 1521[MIME]) may be given to specify the |
633 |
character encoding scheme used to represent the |
634 |
HTML document as a sequence of octets. The default |
635 |
value is outside the scope of this specification; |
636 |
but for example, the default is `US-ASCII' in the |
637 |
context of MIME mail, and `ISO-8859-1' in the |
638 |
context of HTTP. |
639 |
|
640 |
|
641 |
3.2. HTML Document Representation |
642 |
|
643 |
A message entity with a content type of `text/html' |
644 |
represents an HTML document, consisting of a single text |
645 |
entity. The `charset' parameter (whether implicit or |
646 |
explicit) identifies a character encoding scheme. The text |
647 |
entity consists of the characters determined by this |
648 |
character encoding scheme and the octets of the body of the |
649 |
message entity. |
650 |
|
651 |
|
652 |
3.2.1. Undeclared Markup Error Handling |
653 |
|
654 |
To facilitate experimentation and interoperability between |
655 |
implementations of various versions of HTML, the installed |
656 |
base of HTML user agents supports a superset of the HTML 2.0 |
657 |
language by reducing it to HTML 2.0: markup in the form of a |
658 |
start-tag or end-tag whose generic identifier is not |
659 |
declared is mapped to nothing during tokenization. |
660 |
Undeclared attributes are treated similarly. The entire |
661 |
attribute specification of an unknown attribute (i.e., the |
662 |
unknown attribute and its value, if any) should be ignored. |
663 |
On the other hand, references to undeclared entities should |
664 |
be treated as data characters. |
665 |
|
666 |
For example: |
667 |
|
668 |
<div class=chapter><h1>foo</h1><p>...</div> |
669 |
=> <H1>,"foo",</H1>,<P>,"..." |
670 |
xxx <P ID=z23> yyy |
671 |
=> "xxx ",<P>," yyy |
672 |
Let α and β be finite sets. |
673 |
=> "Let α and β be finite sets." |
674 |
|
675 |
Support for notifying the user of such errors is encouraged. |
676 |
|
677 |
Information providers are warned that this convention is not |
678 |
binding: unspecified behavior may result, as such markup is |
679 |
not conforming to this specification. |
680 |
|
681 |
|
682 |
3.2.2. Conventional Representation of Newlines |
683 |
|
684 |
SGML specifies that a text entity is a sequence of records, |
685 |
each beginning with a record start character and ending with |
686 |
a record end character (code positions 10 and 13 |
687 |
respectively) (section 7.6.1, ``Record Boundaries'' in |
688 |
[SGML]). |
689 |
|
690 |
[MIME] specifies that a body of type `text/*' is a sequence |
691 |
of lines, each terminated by CRLF, that is, octets 10, 13. |
692 |
|
693 |
In practice, HTML documents are frequently represented and |
694 |
transmitted using an end of line convention that depends on |
695 |
the conventions of the source of the document; frequently, |
696 |
that representation consists of CR only, LF only, or a CR LF |
697 |
sequence. Hence the decoding of the octets will often result |
698 |
in a text entity with some missing record start and record |
699 |
end characters. |
700 |
|
701 |
Since there is no ambiguity, HTML user agents are encouraged |
702 |
to infer the missing record start and end characters. |
703 |
|
704 |
An HTML user agent should treat end of line in any of its |
705 |
variations as a word space in all contexts except |
706 |
preformatted text. Within preformatted text, an HTML user |
707 |
agent should treat any of the three common representations |
708 |
of end-of-line as starting a new line. |
709 |
|
710 |
|
711 |
3.3. Security Considerations |
712 |
|
713 |
Anchors, embedded images, and all other elements which |
714 |
contain URIs as parameters may cause the URI to be |
715 |
dereferenced in response to user input. In this case, the |
716 |
security considerations of the URI specification apply. |
717 |
|
718 |
The widely deployed methods for submitting forms requests -- |
719 |
HTTP and SMTP -- provide little assurance of |
720 |
confidentiality. Information providers who request sensitive |
721 |
information via forms -- especially by way of the `PASSWORD' |
722 |
type input field (see 7.1.2, "Input Field: INPUT") -- should |
723 |
be aware and make their users aware of the lack of |
724 |
confidentiality. |
725 |
|
726 |
|
727 |
4. Document Structure |
728 |
|
729 |
To identify information as an HTML document conforming to |
730 |
this specification, each document should start with the |
731 |
following prologue: |
732 |
|
733 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> |
734 |
|
735 |
NOTE - If the body of a `text/html' message entity does |
736 |
not begin with a document type declaration, an HTML |
737 |
user agent should infer the above document type |
738 |
declaration. |
739 |
|
740 |
HTML user agents are required to support the above document |
741 |
type declaration and the following document type |
742 |
declarations: |
743 |
|
744 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 2//EN"> |
745 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN"> |
746 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN"> |
747 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN"> |
748 |
|
749 |
They are not required to support other document types, but |
750 |
they may. In particular, they may support other formal |
751 |
public identifiers, or other document types altogether. They |
752 |
may support an internal declaration subset with supplemental |
753 |
entity, element, and other markup declarations, or they may |
754 |
not. |
755 |
|
756 |
|
757 |
4.1. Document Element: <HTML> |
758 |
|
759 |
The HTML document element consists of a head and a body, |
760 |
much like a memo or a mail message. The head contains the |
761 |
title and other optional elements. The body is a text flow |
762 |
consisting of paragraphs, lists, and other elements. |
763 |
|
764 |
|
765 |
4.2. Head: <HEAD> |
766 |
|
767 |
The head of an HTML document is an unordered collection of |
768 |
information about the document. For example: |
769 |
|
770 |
<HEAD> |
771 |
<TITLE>Introduction to HTML</TITLE> |
772 |
</HEAD> |
773 |
|
774 |
|
775 |
4.2.1. Title: <TITLE> |
776 |
|
777 |
Every HTML document must contain a <TITLE> element. |
778 |
|
779 |
The title should identify the contents of the document in a |
780 |
global context. A short title, such as ``Introduction'' may |
781 |
be meaningless out of context. A title such as |
782 |
``Introduction to HTML Elements'' is more appropriate. |
783 |
|
784 |
NOTE - The length of a title is not limited; however, |
785 |
long titles may be truncated in some applications. To |
786 |
minimize this possibility, titles should be fewer than |
787 |
64 characters. |
788 |
|
789 |
A user agent may display the title of a document in a |
790 |
history list or as a label for the window displaying the |
791 |
document. Contrast with headings (4.4, "Headings: H1 ... |
792 |
H6"), which are typically displayed with the body text flow. |
793 |
|
794 |
|
795 |
4.2.2. Base URI: <BASE> |
796 |
|
797 |
The optional <BASE> element specifies the URI of the |
798 |
document, overriding any context otherwise known to the user |
799 |
agent. The required HREF attribute specifies the URI for |
800 |
navigating the document (see 6, "Hyperlinks"). The value of |
801 |
the HREF attribute must be an absolute URI. |
802 |
|
803 |
|
804 |
4.2.3. Keyword Index: <ISINDEX> |
805 |
|
806 |
The <ISINDEX> element indicates that the user agent should |
807 |
allow the user to search an index by giving keywords. See |
808 |
6.3, "Queries and Indexes" for details. |
809 |
|
810 |
|
811 |
4.2.4. Link: <LINK> |
812 |
|
813 |
The <LINK> element represents a hyperlink. It is typically |
814 |
used to indicate authorship, related indexes and glossaries, |
815 |
older or more recent versions, stylesheets, document |
816 |
hierarchy etc. |
817 |
|
818 |
|
819 |
4.2.5. Associated Metainformation: <META> |
820 |
|
821 |
The <META> element is an extensible container for use in |
822 |
identifying, indexing, and cataloging specialized document |
823 |
metainformation. Metainformation has two main functions: |
824 |
|
825 |
* to provide a means to discover that the data set |
826 |
exists and how it might be obtained or accessed; and |
827 |
|
828 |
* to document the content, quality, and features of a |
829 |
data set and so give an indication of its fitness for |
830 |
use. |
831 |
|
832 |
Each <META> element specifies a name/value pair. If multiple |
833 |
META elements are provided with the same name, their |
834 |
combined contents--concatenated as a comma-separated |
835 |
list--is the value associated with that name. |
836 |
|
837 |
NOTE - The <META> element should not be used where a |
838 |
specific element such as <TITLE> would be appropriate. |
839 |
|
840 |
HTTP servers should read the content of the document <HEAD> |
841 |
to generate header fields corresponding to any elements |
842 |
defining a value for the attribute HTTP-EQUIV. |
843 |
|
844 |
NOTE - The method by which the server extracts document |
845 |
metainformation is unspecified and not mandatory. The |
846 |
META element only provides an extensible mechanism for |
847 |
identifying and embedding document metainformation - |
848 |
how it may be used is up to the individual server |
849 |
implementation and the HTML user agent. |
850 |
|
851 |
Attributes of the META element: |
852 |
|
853 |
HTTP-EQUIV |
854 |
This attribute binds the element to an HTTP header |
855 |
field. An HTTP server may use this information to |
856 |
process the doducment. In particular, it should |
857 |
include a header field in the responses to GET |
858 |
requests for this document: the header name is |
859 |
taken from the HTTP-EQUIV attribute value, and the |
860 |
header value is taken from the value of the |
861 |
CONTENT attribute. HTTP header names are not case |
862 |
sensitive. |
863 |
|
864 |
NAME |
865 |
name of the name/value pair. If not present, |
866 |
HTTP-EQUIV gives the name. |
867 |
|
868 |
CONTENT |
869 |
The value of the name/value pair. |
870 |
|
871 |
Examples |
872 |
|
873 |
If the document contains: |
874 |
|
875 |
<META HTTP-EQUIV="Expires" |
876 |
CONTENT="Tue, 04 Dec 1993 21:29:02 GMT"> |
877 |
<meta http-equiv="Keywords" CONTENT="Fred, Barney"> |
878 |
<META HTTP-EQUIV="Reply-to" |
879 |
content="fielding@ics.uci.edu (Roy Fielding)"> |
880 |
|
881 |
then the server should include the following header fields: |
882 |
|
883 |
Expires: Tue, 04 Dec 1993 21:29:02 GMT |
884 |
Keywords: Fred, Barney |
885 |
Reply-to: fielding@ics.uci.edu (Roy Fielding) |
886 |
|
887 |
as part of the HTTP response to a `GET' or `HEAD' request |
888 |
for that document. |
889 |
|
890 |
When the HTTP-EQUIV attribute is not present, the server |
891 |
should not generate an HTTP response header for the |
892 |
metainformation; e.g., |
893 |
|
894 |
Do not name an HTTP-EQUIV equal to a response header that |
895 |
should normally only be generated by the HTTP server. |
896 |
Example names that are inappropriate include `Server', |
897 |
`Date', and `Last-modified' -- the exact list of |
898 |
inappropriate names is dependent on the particular server |
899 |
implementation. |
900 |
|
901 |
|
902 |
4.2.6. Next Id: <NEXTID> |
903 |
|
904 |
They <NEXTID> element gives a hint for the name to use for |
905 |
an <A> element when editing an HTML document. It should be |
906 |
distinct from all NAME attribute values on <A> elements. For |
907 |
example: |
908 |
|
909 |
<NEXTID N=Z27> |
910 |
|
911 |
|
912 |
4.3. Body: <BODY> |
913 |
|
914 |
The <BODY> element contains the text flow of the document, |
915 |
including headings, paragraphs, lists, etc. |
916 |
|
917 |
For example: |
918 |
|
919 |
<BODY> |
920 |
<h1>Important Stuff</h1> |
921 |
<p>Explanation about important stuff... |
922 |
</BODY> |
923 |
|
924 |
|
925 |
4.4. Headings: <H1> ... <H6> |
926 |
|
927 |
The six heading elements, <H1> through <H6>, denote section |
928 |
headings. Although the order and occurence of headings is |
929 |
not constrained by the HTML DTD, documents should not skip |
930 |
levels (for example, from H1 to H3), as converting such |
931 |
documents to other representations is often problematic. |
932 |
|
933 |
Example of use: |
934 |
|
935 |
<H1>This is a heading</H1> |
936 |
Here is some text |
937 |
<H2>Second level heading</H2> |
938 |
Here is some more text. |
939 |
|
940 |
Typical renderings are: |
941 |
|
942 |
H1 |
943 |
Bold, very-large font, centered. One or two blank |
944 |
lines above and below. |
945 |
|
946 |
H2 |
947 |
Bold, large font, flush-left. One or two blank |
948 |
lines above and below. |
949 |
|
950 |
H3 |
951 |
Italic, large font, slightly indented from the |
952 |
left margin. One or two blank lines above and |
953 |
below. |
954 |
|
955 |
H4 |
956 |
Bold, normal font, indented more than H3. One |
957 |
blank line above and below. |
958 |
|
959 |
H5 |
960 |
Italic, normal font, indented as H4. One blank |
961 |
line above. |
962 |
|
963 |
H6 |
964 |
Bold, indented same as normal text, more than H5. |
965 |
One blank line above. |
966 |
|
967 |
|
968 |
4.5. Block Structuring Elements |
969 |
|
970 |
Each of the following elements defines a block structure; |
971 |
that is, they indicate a paragraph break before and after. |
972 |
|
973 |
|
974 |
4.5.1. Paragraph: <P> |
975 |
|
976 |
The <P> element indicates a paragraph. The exact |
977 |
indentation, leading space, etc. of a paragraph is not |
978 |
specified and may be a function of other tags, style sheets, |
979 |
etc. |
980 |
|
981 |
Typically, paragraphs are surrounded by a vertical space of |
982 |
one line or half a line. The first line in a paragraph is |
983 |
indented in some cases. |
984 |
|
985 |
Example of use: |
986 |
|
987 |
<H1>This Heading Precedes the Paragraph</H1> |
988 |
<P>This is the text of the first paragraph. |
989 |
<P>This is the text of the second paragraph. Although you do not |
990 |
need to start paragraphs on new lines, maintaining this |
991 |
convention facilitates document maintenance.</P> |
992 |
<P>This is the text of a third paragraph.</P> |
993 |
|
994 |
|
995 |
4.5.2. Preformatted Text: <PRE> |
996 |
|
997 |
The <PRE> element represents a character cell block of |
998 |
textand so is suitable for text that has been formatted on |
999 |
screen. |
1000 |
|
1001 |
The <PRE> tag may be used with the optional WIDTH attribute. |
1002 |
The WIDTH attribute specifies the maximum number of |
1003 |
characters for a line and allows the HTML user agent to |
1004 |
select a suitable font and indentation. |
1005 |
|
1006 |
Within preformatted text: |
1007 |
|
1008 |
* Line breaks within the text are rendered as a move to |
1009 |
the beginning of the next line. |
1010 |
|
1011 |
NOTE - References to the ``beginning of a new line'' do |
1012 |
not imply that the renderer is forbidden from using a |
1013 |
constant left indent for rendering preformatted text. |
1014 |
The left indent may be constrained by the width |
1015 |
required. |
1016 |
|
1017 |
* Anchor elements and phrase markup may be used. |
1018 |
|
1019 |
NOTE - Within a Preformatted Text element, the |
1020 |
constraint that the rendering must be on a fixed |
1021 |
horizontal character pitch may limit or prevent the |
1022 |
ability of the HTML user agent to faithfully render |
1023 |
phrase markup. |
1024 |
|
1025 |
* Elements that define paragraph formatting (headings, |
1026 |
address, etc.) must not be used. |
1027 |
|
1028 |
NOTE - Som historical documents contain <P> tags in |
1029 |
<PRE> elements. User agents are engcouraged to treat |
1030 |
this a a line break. A <P> tag followed by a newline |
1031 |
character should produce only one line break, not a |
1032 |
line break plus a blank line. |
1033 |
|
1034 |
* The horizontal tab character (encoded in `US-ASCII' |
1035 |
and `ISO-8859-1' as decimal 9) must be interpreted as |
1036 |
the smallest positive nonzero number of spaces which |
1037 |
will leave the number of characters so far on the line |
1038 |
as a multiple of 8. |
1039 |
|
1040 |
Example of use: |
1041 |
|
1042 |
<PRE> |
1043 |
This is an example line. |
1044 |
</PRE> |
1045 |
|
1046 |
|
1047 |
4.5.3. Address: <ADDRESS> |
1048 |
|
1049 |
The <ADDRESS> element specifies such information as address, |
1050 |
signature and authorship, often at the beginning or end of |
1051 |
the body of a document. |
1052 |
|
1053 |
Typically, the <ADDRESS> element is rendered in an italic |
1054 |
typeface and may be indented. |
1055 |
|
1056 |
Example of use: |
1057 |
|
1058 |
<ADDRESS> |
1059 |
Newsletter editor<BR> |
1060 |
J.R. Brown<BR> |
1061 |
JimquickPost News, Jumquick, CT 01234<BR> |
1062 |
Tel (123) 456 7890 |
1063 |
</ADDRESS> |
1064 |
|
1065 |
|
1066 |
4.5.4. Block Quote: <BLOCKQUOTE> |
1067 |
|
1068 |
The <BLOCKQUOTE> element contains text quoted from another |
1069 |
source. |
1070 |
|
1071 |
A typical rendering might be a slight extra left and right |
1072 |
indent, and/or italic font. The <BLOCKQUOTE> typically |
1073 |
provides space above and below the quote. |
1074 |
|
1075 |
Single-font rendition may reflect the quotation style of |
1076 |
Internet mail by putting a vertical line of graphic |
1077 |
characters, such as the greater than symbol (>), in the left |
1078 |
margin. |
1079 |
|
1080 |
Example of use: |
1081 |
|
1082 |
I think the poem ends |
1083 |
<BLOCKQUOTE> |
1084 |
<P>Soft you now, the fair Ophelia. Nymph, in thy orisons, be all |
1085 |
my sins remembered. |
1086 |
</BLOCKQUOTE> |
1087 |
but I am not sure. |
1088 |
|
1089 |
|
1090 |
4.6. List Elements |
1091 |
|
1092 |
HTML includes a number of list elements. They may be used in |
1093 |
combination; for example, a <OL> may be nested in an <LI> |
1094 |
element of a <UL>. |
1095 |
|
1096 |
|
1097 |
4.6.1. Unordered List: <UL>, <LI> |
1098 |
|
1099 |
The <UL> represents a list of items with no inherent |
1100 |
ordering -- typically a bulleted list. |
1101 |
|
1102 |
The content of a <UL> element is a sequence of <LI> |
1103 |
elements. For example: |
1104 |
|
1105 |
<UL> |
1106 |
<LI>First list item |
1107 |
<LI>Second list item |
1108 |
<p>second paragraph of second item |
1109 |
<LI>Third list item |
1110 |
</UL> |
1111 |
|
1112 |
|
1113 |
4.6.2. Ordered List: <OL> |
1114 |
|
1115 |
The <UL> element represents an ordered list of items, sorted |
1116 |
by sequence or order of importance. |
1117 |
|
1118 |
The content of a <OL> element is a sequence of <LI> |
1119 |
elements. For example: |
1120 |
|
1121 |
<OL> |
1122 |
<LI>Click the Web button to open the Open the URI window. |
1123 |
<LI>Enter the URI number in the text field of the Open URI |
1124 |
window. The Web document you specified is displayed. |
1125 |
<ol> |
1126 |
<li>substep 1 |
1127 |
<li>substep 2 |
1128 |
</ol> |
1129 |
<LI>Click highlighted text to move from one link to another. |
1130 |
</OL> |
1131 |
|
1132 |
The COMPACT attribute suggests that a compact rendering be |
1133 |
used. |
1134 |
|
1135 |
|
1136 |
4.6.3. Directory List: <DIR> |
1137 |
|
1138 |
The <DIR> element is similar to the <UL> element. It |
1139 |
represents a list of short items, typically up to 20 |
1140 |
characters each. Items in a directory list may be arranged |
1141 |
in columns, typically 24 characters wide. |
1142 |
|
1143 |
The content of a <OL> element is a sequence of <LI> |
1144 |
elements. Nested block elements are not allowed in the |
1145 |
content of <DIR> elements. For example: |
1146 |
|
1147 |
<DIR> |
1148 |
<LI>A-H<LI>I-M |
1149 |
<LI>M-R<LI>S-Z |
1150 |
</DIR> |
1151 |
|
1152 |
|
1153 |
4.6.4. Menu List: <MENU> |
1154 |
|
1155 |
The <MENU> element is a list of items with typically one |
1156 |
line per item. The menu list style is typically more compact |
1157 |
than the style of an unordered list. |
1158 |
|
1159 |
The content of a <MENU> element is a sequence of <LI> |
1160 |
elements. Nested block elements are not allowed in the |
1161 |
content of <MENU> elements. For example: |
1162 |
|
1163 |
<MENU> |
1164 |
<LI>First item in the list. |
1165 |
<LI>Second item in the list. |
1166 |
<LI>Third item in the list. |
1167 |
</MENU> |
1168 |
|
1169 |
|
1170 |
4.6.5. Definition List: <DL>, <DT>, <DD> |
1171 |
|
1172 |
A definition list is a list of terms and corresponding |
1173 |
definitions. Definition lists are typically formatted with |
1174 |
the term flush-left and the definition, formatted paragraph |
1175 |
style, indented after the term. |
1176 |
|
1177 |
Example of use: |
1178 |
|
1179 |
<DL> |
1180 |
<DT>Term<DD>This is the definition of the first term. |
1181 |
<DT>Term<DD>This is the definition of the second term. |
1182 |
</DL> |
1183 |
|
1184 |
If the DT term does not fit in the DT column (one third of |
1185 |
the display area), it may be extended across the page with |
1186 |
the DD section moved to the next line, or it may be wrapped |
1187 |
onto successive lines of the left hand column. |
1188 |
|
1189 |
The optional COMPACT attribute suggests that a compact |
1190 |
rendering be used, because the list items are small and/or |
1191 |
the entire list is large. |
1192 |
|
1193 |
Unless the COMPACT attribute is present, an HTML user agent |
1194 |
may leave white space between successive DT, DD pairs. The |
1195 |
COMPACT attribute may also reduce the width of the left-hand |
1196 |
(DT) column. |
1197 |
|
1198 |
<DL COMPACT> |
1199 |
<DT>Term<DD>This is the first definition in compact format. |
1200 |
<DT>Term<DD>This is the second definition in compact format. |
1201 |
</DL> |
1202 |
|
1203 |
|
1204 |
4.7. Phrase Markup |
1205 |
|
1206 |
Phrases may be marked up according to idiomatic usage, |
1207 |
typographic appearance, or for use as hyperlink anchors. |
1208 |
|
1209 |
User agents must render highlighted phrases distinctly from |
1210 |
plain text. Additionally, <EM> content must be rendered as |
1211 |
distinct from <STRONG> content, and <B> content must |
1212 |
rendered as distinct from <I> content. |
1213 |
|
1214 |
Phrase elements may be nested within the content of other |
1215 |
phrase elements; however, HTML user agents may render nested |
1216 |
phrase elements indistinctly from non-nested elements: |
1217 |
|
1218 |
plain <B>bold <I>italic</I></B> may the rendered |
1219 |
the same as plain <B>bold </B><I>italic</I> |
1220 |
|
1221 |
|
1222 |
4.7.1. Idiomatic Elements |
1223 |
|
1224 |
|
1225 |
4.7.1.1. Citation: <CITE> |
1226 |
|
1227 |
The <CITE> element is used to indicate the title of a book |
1228 |
or other citation. It is typically typeset as italics. For |
1229 |
example: |
1230 |
|
1231 |
He just couldn't get enough of <cite>The Grapes of Wrath</cite>. |
1232 |
|
1233 |
|
1234 |
4.7.1.2. Code: <CODE> |
1235 |
|
1236 |
The <CODE> element indicates an example of code, typically |
1237 |
rendered in a monospaced font. Contrast with the <PRE> block |
1238 |
structuring element in 4.5.2, "Preformatted Text: PRE". For |
1239 |
example: |
1240 |
|
1241 |
The expression <code>x += 1</code> is short for <code>x = x + 1</code>. |
1242 |
|
1243 |
|
1244 |
4.7.1.3. Emphasis: <EM> |
1245 |
|
1246 |
The <EM> element indicates an emphasized phrase, typically |
1247 |
rendered as italics. For example: |
1248 |
|
1249 |
A singular subject <em>always</em> takes a singular verb. |
1250 |
|
1251 |
|
1252 |
4.7.1.4. Keyboard: <KBD> |
1253 |
|
1254 |
The Keyboard element indicates text typed by a user, |
1255 |
typically rendered in a monospaced font. This is commonly |
1256 |
used in instruction manuals. For example: |
1257 |
|
1258 |
Enter <kbd>FIND IT</kbd> to search the database. |
1259 |
|
1260 |
|
1261 |
4.7.1.5. Sample: <SAMP> |
1262 |
|
1263 |
The <SAMP> element indicates a sequence of literal |
1264 |
characters, typically rendered in a monospaced font. For |
1265 |
example: |
1266 |
|
1267 |
The only word containing the letters <samp>mt</samp> is dreamt. |
1268 |
|
1269 |
|
1270 |
4.7.1.6. Strong Empasis: <STRONG> |
1271 |
|
1272 |
The <STRONG> element indicates strong emphasis, typically |
1273 |
rendered in bold. For example: |
1274 |
|
1275 |
<strong>STOP</strong>, or I'll say "<strong>STOP</strong>" again!. |
1276 |
|
1277 |
|
1278 |
4.7.1.7. Variable: <VAR> |
1279 |
|
1280 |
The <VAR> element indicates a placeholder, typically |
1281 |
rendered as italic. For example: |
1282 |
|
1283 |
Take a guess: Roses are <var>blank</var>. |
1284 |
|
1285 |
|
1286 |
4.7.2. Typographic Elements |
1287 |
|
1288 |
Typographic elements are used to specify the format of |
1289 |
marked text. |
1290 |
|
1291 |
Typical renderings for idomatic elements vary between user |
1292 |
agents. If a specific rendering is necessary -- for example, |
1293 |
when referring to a specific text attribute as in ``The |
1294 |
italic parts are mandatory'' -- a typographic element can be |
1295 |
used to ensure that the intended typography is used where |
1296 |
possible. |
1297 |
|
1298 |
|
1299 |
4.7.2.1. Bold: <B> |
1300 |
|
1301 |
The <B> element indicated bold text. Where bold typography |
1302 |
is unavailable, an alternative representation may be used. |
1303 |
|
1304 |
|
1305 |
4.7.2.2. Italic: <I> |
1306 |
|
1307 |
The <I> element indicated italic text. Where italic |
1308 |
typography is unavailable, an alternative representation may |
1309 |
be used. |
1310 |
|
1311 |
|
1312 |
4.7.2.3. Typewriter: <TT> |
1313 |
|
1314 |
The <TT> element indicates typewriter text. Where a |
1315 |
typewriter font is unavailable, an alternative |
1316 |
representation may be used. |
1317 |
|
1318 |
|
1319 |
4.7.3. Anchor: <A> |
1320 |
|
1321 |
The <A> element indicates the source and/or destination of a |
1322 |
hyperlink (see 6, "Hyperlinks"). At least one of the NAME |
1323 |
and HREF attributes should be given. Attributes of the <A> |
1324 |
element: |
1325 |
|
1326 |
HREF |
1327 |
gives the destination of a hyperlink. |
1328 |
|
1329 |
NAME |
1330 |
gives the name of the anchor, and makes it |
1331 |
available as a navigation destination. |
1332 |
|
1333 |
TITLE |
1334 |
suggests a title for the destination resource -- |
1335 |
advisory only. The TITLE attribute may be used: |
1336 |
|
1337 |
* for display prior to accessing the destination |
1338 |
resource, for example, as a margin note or on a small |
1339 |
box while the mouse is over the anchor, or while the |
1340 |
document is being loaded; |
1341 |
|
1342 |
* for resources that do not specify a title such as |
1343 |
graphics, plain text and Gopher menus, for use as a |
1344 |
window title. |
1345 |
|
1346 |
REL |
1347 |
The REL attribute gives the relationship(s) |
1348 |
described by the hyperlink. The value is a |
1349 |
whitespace separated list of relationship names. |
1350 |
|
1351 |
REV |
1352 |
same as the REL attribute, but the semantics of |
1353 |
the relationship are in the reverse direction. A |
1354 |
link from A to B with REL=``X'' expresses the same |
1355 |
relationship as a link from B to A with REV=``X''. |
1356 |
An anchor may have both REL and REV attributes. |
1357 |
|
1358 |
URN |
1359 |
specifies a preferred, more persistent identifier |
1360 |
for the destination. The format of URNs is under |
1361 |
discussion (1995) by various working groups of the |
1362 |
Internet Engineering Task Force. |
1363 |
|
1364 |
METHODS |
1365 |
specifies methods to be used in accessing the |
1366 |
destination, as a whitespace-separated list of |
1367 |
names. For similar reasons as for the TITLE |
1368 |
attribute, it may be useful to include the |
1369 |
information in advance in the link. For example, |
1370 |
the HTML user agent may chose a different |
1371 |
rendering as a function of the methods allowed; |
1372 |
for example, something that is searchable may get |
1373 |
a different icon. |
1374 |
|
1375 |
|
1376 |
4.8. Line Break: <BR> |
1377 |
|
1378 |
The <BR> element specifies a line break between words (see |
1379 |
5, "Character, Words, and Paragraphs"). For example: |
1380 |
|
1381 |
<P> Pease porridge hot<BR> |
1382 |
Pease porridge cold<BR> |
1383 |
Pease porridge in the pot<BR> |
1384 |
Nine days old. |
1385 |
|
1386 |
|
1387 |
4.9. Horizontal Rule: <HR> |
1388 |
|
1389 |
The <HR> element is a divider between sections of text; |
1390 |
typcially a full width horizontal rule or equivalent |
1391 |
graphic. For example: |
1392 |
|
1393 |
<HR> |
1394 |
<ADDRESS>February 8, 1995, CERN</ADDRESS> |
1395 |
</BODY> |
1396 |
|
1397 |
|
1398 |
4.10. Image: <IMG> |
1399 |
|
1400 |
The <IMG> element refers to an image or icon. |
1401 |
|
1402 |
HTML user agents that cannot process images ignore the <IMG> |
1403 |
element unless it the ALT attribute is present. |
1404 |
|
1405 |
NOTE - Some HTML user agents can process graphics |
1406 |
linked via anchors , but not <IMG> graphics. If a |
1407 |
graphic is essential, it should be referenced from an |
1408 |
<A> element rather than in <IMG> element.If the graphic |
1409 |
is not essential, then the <IMG> element is |
1410 |
appropriate. |
1411 |
|
1412 |
Attributes of the <IMG> element: |
1413 |
|
1414 |
ALIGN |
1415 |
alignment of the image with respect to the text |
1416 |
baseline. * `TOP' specifies that the top of the image |
1417 |
aligns with the tallest item on the line contianing the |
1418 |
image. |
1419 |
|
1420 |
* `MIDDLE' specifies that the center of the image |
1421 |
aligns with the baseline of the line containing the |
1422 |
image. |
1423 |
|
1424 |
* `BOTTOM' specifies that the bottom of the image |
1425 |
aligns with the baseline of the line containing the |
1426 |
image. |
1427 |
|
1428 |
ALT |
1429 |
Optional alternative text, for use in |
1430 |
non-graphical environments. |
1431 |
|
1432 |
ISMAP |
1433 |
indicates an image map (see 6.4, "Image Maps"). |
1434 |
|
1435 |
SRC |
1436 |
specifies the URI of the image resource. |
1437 |
|
1438 |
NOTE - In practice, the media types of image resources |
1439 |
are limited to a few raster graphic formats: typically |
1440 |
`image/gif', `image/jpeg'. In particular, `text/html' |
1441 |
resources are not intended to be used as image |
1442 |
resources. |
1443 |
|
1444 |
Examples of use: |
1445 |
|
1446 |
<IMG SRC="triangle.xbm" ALT="Warning:"> Be sure |
1447 |
to read these instructions. |
1448 |
|
1449 |
<IMG SRC="triangle.xbm">Be sure to read these |
1450 |
instructions. |
1451 |
|
1452 |
<a href="http://machine/htbin/imagemap/sample"> |
1453 |
<IMG SRC="sample.xbm" ISMAP> |
1454 |
</a> |
1455 |
|
1456 |
|
1457 |
5. Character, Words, and Paragraphs |
1458 |
|
1459 |
An HTML user agent should present the body of an HTML |
1460 |
document as a collection of typeset paragraphs and |
1461 |
preformatted text. Except for the <PRE> element, each block |
1462 |
structuring element is regarded as a paragraph by taking the |
1463 |
data characters in its content and the content of its |
1464 |
descendant elements, concatenating them, and splitting the |
1465 |
result into words, separated by space, tab, or record end |
1466 |
characters (and perhaps hyphen characters). The sequence of |
1467 |
words is typeset as a paragraph by breaking it into lines. |
1468 |
|
1469 |
|
1470 |
5.1. The ISO Latin 1 Character Repertoire |
1471 |
|
1472 |
The minimum character repertoire supported by all conforming |
1473 |
HTML user agents is Latin Alphabet Nr. 1, or simply Latin-1. |
1474 |
Latin-1 includes characters from most Western European |
1475 |
languages, as well as a number of control characters. |
1476 |
Latin-1 also includes a non-breaking space, a soft hyphen |
1477 |
indicator, 93 graphical characters, 8 unassigned characters, |
1478 |
and 25 control characters. |
1479 |
|
1480 |
NOTE - Use the non-breaking space and soft hyphen |
1481 |
indicator characters is discouraged because support for |
1482 |
them is not widely deployed. |
1483 |
|
1484 |
NOTE - To support non-western writing systems, a larger |
1485 |
character repertoire will be specified in a future |
1486 |
version of HTML. The document character set will be |
1487 |
ISO/IEC 10646-1, or some subset that agrees with |
1488 |
ISO/IEC 10646-1; in particular, all numeric character |
1489 |
references must use code positions assigned by ISO/IEC |
1490 |
10646-1. |
1491 |
|
1492 |
In SGML applications, the use of control characters is |
1493 |
limited in order to maximize the chance of successful |
1494 |
interchange over heterogeneous networks and operating |
1495 |
systems. In HTML, only three control characters are allowed: |
1496 |
Horizontal Tab (HT, encoded as 9 decimal in `US-ASCII' and |
1497 |
`ISO-8859-1'), Carriage Return, and Line Feed. |
1498 |
|
1499 |
The HTML DTD references the Added Latin 1 entity set, to |
1500 |
allow mnemonic representation of Latin 1 characters using |
1501 |
only the widely supported ASCII character repertoire. For |
1502 |
example: |
1503 |
|
1504 |
Kurt Gödel was a famous logician and mathematician. |
1505 |
|
1506 |
See 8.4.2, "ISO Latin 1 Character Entity Set" for a table of |
1507 |
the ``Added Latin 1'' entities, and 11.1, "The ANSI/ISO |
1508 |
8859-1 Coded Character Set" for a table of the code |
1509 |
positions of ANSI/ISO 8859-1. |
1510 |
|
1511 |
|
1512 |
6. Hyperlinks |
1513 |
|
1514 |
In addition to general purpose elements such as paragraphs |
1515 |
and lists, HTML documents can express hyperlinks. A |
1516 |
hyperlink is a relationship between two resources, called |
1517 |
the source and the destination of the hyperlink. Each |
1518 |
resource has a Uniform Resource Identifier (URI). |
1519 |
|
1520 |
An HTML user agent allows navigating a collection of these |
1521 |
resources. In the following interactions, the URI of the |
1522 |
source document is called the base URI. |
1523 |
|
1524 |
|
1525 |
6.1. Accessing Resources |
1526 |
|
1527 |
Each of the following markup constructs is the source of a |
1528 |
hyperlink; these hyperlinks are references to resources to |
1529 |
be processed in conjunction with the source documents: |
1530 |
|
1531 |
* <IMG> elements |
1532 |
|
1533 |
* <INPUT> elements with the SRC attribute present |
1534 |
|
1535 |
* <LINK> element |
1536 |
|
1537 |
To access the destination of a hyperlink, the base URI of |
1538 |
the source document is combined with the value of the HREF |
1539 |
or SRC attribute of the hyperlink element according to |
1540 |
[RELURL]. The user agent disregards any fragment identifer, |
1541 |
and uses the resulting URI to access the destination |
1542 |
resource. For example, if a document identified as |
1543 |
`http://host/x/y.html' contains: |
1544 |
|
1545 |
<img src="../icons/abc.gif"> |
1546 |
|
1547 |
then the user agent must use the URI |
1548 |
`http://host/icons/abc.gif' to access the resource linked |
1549 |
from the <IMG> element. |
1550 |
|
1551 |
|
1552 |
6.2. Traversing Hyperlinks |
1553 |
|
1554 |
An <A> element with the HREF attribute present is an anchor; |
1555 |
that is, the source of a hyperlink that is an option to |
1556 |
navigate to another resource. The <LINK> element may also be |
1557 |
an anchor. |
1558 |
|
1559 |
In addition to the base URI, the state of an HTML user agent |
1560 |
includes a list of the anchors in the document. The user can |
1561 |
traverse a hyperlink by choosing an anchor. The user agent |
1562 |
then accesses the destination document as above and presents |
1563 |
it. |
1564 |
|
1565 |
|
1566 |
6.2.1. Fragment Identifiers |
1567 |
|
1568 |
If the value of the <HREF> attribute of an anchor element |
1569 |
contains a `#' character, then the characters after the `#' |
1570 |
are a fragment identifier, not a part of the destination |
1571 |
URI. As a degenerate case, `HREF="#fragment"' refers to an |
1572 |
anchor in the same document: the source and destination URIs |
1573 |
are the same. |
1574 |
|
1575 |
After accessing the destination resource, the navigation |
1576 |
state (the scrollbar, for example) may be modified by a |
1577 |
fragment identifer in the hyperlink source markup. The |
1578 |
meaning of fragment identifiers depends on the media type of |
1579 |
the destination resource. For `text/html' resources, it |
1580 |
instructs the user agent to locate the <A> element with a |
1581 |
NAME attribute whose value is the same as the fragment |
1582 |
identifier. The matching is case sensitive. |
1583 |
|
1584 |
For example, if a user agent was processing the above |
1585 |
document and the user indicated the following anchor: |
1586 |
|
1587 |
<p> See: <a href="app1.html#bannanas">appendix 1</a> for more detail |
1588 |
on bannanas.</a> |
1589 |
|
1590 |
then the user agent URI must access the resource |
1591 |
`http://host/x/app1.html'. Assuming the resource is |
1592 |
represented using the `text/html' media type, the user agent |
1593 |
must locate the anchor named `bannanas' and begin navigation |
1594 |
there. |
1595 |
|
1596 |
The base URI for navigating the destination document may be |
1597 |
different from the URI used to access it. For example, it |
1598 |
may be replaced by by a <BASE> tag in the destination |
1599 |
document or by an HTTP redirection transaction. |
1600 |
|
1601 |
|
1602 |
6.3. Queries and Indexes |
1603 |
|
1604 |
The <ISINDEX> element represents a set of hyperlinks. The |
1605 |
user can choose from the set by providing keywords to the |
1606 |
user agent. The user agent computes the destination URI by |
1607 |
appending `?' and the keywords to the base URI. The keywords |
1608 |
are escaped according to [URL] and joined by `+'. For |
1609 |
example, if a document contains: |
1610 |
|
1611 |
<BASE HREF="http://host/index"> |
1612 |
<ISINDEX> |
1613 |
|
1614 |
and the user provides the keywords `apple' and `berry', then |
1615 |
the user agent must access the resource |
1616 |
`http://host/index?apple+berry'. |
1617 |
|
1618 |
<FORM> elements with `METHOD=GET' also represent sets of |
1619 |
hyperlinks. See 7.2.2, "Query Forms: METHOD=GET" for |
1620 |
details. |
1621 |
|
1622 |
|
1623 |
6.4. Image Maps |
1624 |
|
1625 |
The ISMAP attribute in combination with the <A> and <IMG> |
1626 |
elements, represents a set of hyperlinks. The user can |
1627 |
choose from the set by choosing a pixel of the image. The |
1628 |
user agent computes the destination URI by appending `?' and |
1629 |
the coordinates of the pixel to the URI given in the <A> |
1630 |
element. For example, if a document contains: |
1631 |
|
1632 |
<head><title>ImageMap Example</title> |
1633 |
<BASE HREF="http://host/index"></head> |
1634 |
<body> |
1635 |
<p> Choose any of these icons:<br> |
1636 |
<a href="/cgi-bin/imagemap"><img ismap src="icons.gif"></a> |
1637 |
|
1638 |
and the user chooses the upper-leftmost pixel, then chosen |
1639 |
hyperlink is the one with the URI |
1640 |
`http://host/cgi-bin/image?0,0'. |
1641 |
|
1642 |
|
1643 |
7. Forms |
1644 |
|
1645 |
A form is a template for a form data set -- sequence of |
1646 |
name/value pair fields -- with an associated method and |
1647 |
action URI. The names are specified on the NAME attributes |
1648 |
of form input elements, and the values are given by the |
1649 |
user. The resulting form data set is used to access an |
1650 |
information service as a function of the action and method. |
1651 |
|
1652 |
Forms elements can be mixed in with document structuring |
1653 |
elements. For example, a <PRE> element may contain a <FORM> |
1654 |
element, or a <FORM> element may contain lists which contain |
1655 |
<INPUT> elements. This gives considerable flexibility in |
1656 |
designing the layout of forms. |
1657 |
|
1658 |
Form processing is a level 2 feature. |
1659 |
|
1660 |
|
1661 |
7.1. Form Elements |
1662 |
|
1663 |
|
1664 |
7.1.1. Form: <FORM> |
1665 |
|
1666 |
The <FORM> element contains a sequence of input elements, |
1667 |
along with document structuring elements. The attributes |
1668 |
are: |
1669 |
|
1670 |
ACTION |
1671 |
specifies the action URI for the form. The ACTION |
1672 |
attribute defaults to the base URI of the document |
1673 |
(see 6, "Hyperlinks"). |
1674 |
|
1675 |
METHOD |
1676 |
selects a method of accessing the action URI. |
1677 |
|
1678 |
ENCTYPE |
1679 |
specifies the media type used to encode the |
1680 |
name/value pairs for transport, in case the |
1681 |
protocol does not itself impose a format. |
1682 |
|
1683 |
|
1684 |
7.1.2. Input Field: <INPUT> |
1685 |
|
1686 |
The <INPUT> element represents a field for user input. |
1687 |
Attributes are: |
1688 |
|
1689 |
ALIGN |
1690 |
vertical alignment of the image. For use only with |
1691 |
`TYPE=IMAGE'. The possible values are as for the |
1692 |
ALIGN attribute of the <IMG> element (see 4.10, |
1693 |
"Image: IMG"). |
1694 |
|
1695 |
CHECKED |
1696 |
indicates that the initial state of a checkbox or |
1697 |
radio button is selected. |
1698 |
|
1699 |
MAXLENGTH |
1700 |
constrains the number of characters that can be |
1701 |
entered into a text input field. If the value of |
1702 |
MAXLENGTH is greater the the value of the SIZE |
1703 |
attribute, the field should scroll appropriately. |
1704 |
The default number of characters is unlimited. |
1705 |
|
1706 |
NAME |
1707 |
symbolic name for the form field corresponding to |
1708 |
this element or group of elements. |
1709 |
|
1710 |
SIZE |
1711 |
specifies the amount of display space allocated to |
1712 |
this input field according to its type. |
1713 |
|
1714 |
SRC |
1715 |
A URI specifying an image resource. For use only |
1716 |
with `TYPE=IMAGE'. |
1717 |
|
1718 |
TYPE |
1719 |
indicates type of the field. Defaults to `TEXT'. |
1720 |
Values are: |
1721 |
|
1722 |
CHECKBOX |
1723 |
an independent boolean value. |
1724 |
|
1725 |
HIDDEN |
1726 |
a hidden field. The user does not interact with |
1727 |
this field; instead, the VALUE attribute can be |
1728 |
used to specify a value. |
1729 |
|
1730 |
IMAGE |
1731 |
specifies an image resource to display, and allows |
1732 |
input of two form data: the x and y coordinate of |
1733 |
a pixel chosen from the image. The names of the |
1734 |
data are the name of this element with `.x' and |
1735 |
`.y' appended. `TYPE=IMAGE' implies `TYPE=SUBMIT' |
1736 |
processing; that is, when a pixel is chosen, the |
1737 |
form as a whole is submitted. |
1738 |
|
1739 |
PASSWORD |
1740 |
Similar to the TEXT attribute, except that the |
1741 |
value is obscured as it is entered. |
1742 |
|
1743 |
RADIO |
1744 |
a 1-of-many choice. All <INPUT> elements with |
1745 |
`TYPE=RADIO' and the same NAME combine into one |
1746 |
form field. The value of the form field is the |
1747 |
VALUE of the element chosen by the user. The |
1748 |
initial state may be indicated with the CHECKED |
1749 |
attribute. The VALUE attribute is required for |
1750 |
radio inputs. |
1751 |
|
1752 |
RESET |
1753 |
an input option, typically a button, that |
1754 |
instructs the user agent to reset the form's |
1755 |
fields to their initial states. Any VALUE |
1756 |
attribute indicates a label for the input |
1757 |
(button). |
1758 |
|
1759 |
SUBMIT |
1760 |
an input option, typically a button, that |
1761 |
instructs the user agent to submit the form. Any |
1762 |
VALUE attribute indicates a label for the input |
1763 |
(button). If the NAME attribute is present, this |
1764 |
element contributes a form field whose value is |
1765 |
given by the VALUE attribute. If the NAME |
1766 |
attribute is not present, this element does not |
1767 |
contribute a form field. |
1768 |
|
1769 |
TEXT |
1770 |
a single line text entry fields. The SIZE and |
1771 |
MAXLENGTH attributes may be used to constrain the |
1772 |
input or layout of the field. Use the <TEXTAREA> |
1773 |
element for mulit-line text fields. |
1774 |
|
1775 |
VALUE |
1776 |
The initial value of the field. |
1777 |
|
1778 |
|
1779 |
7.1.3. Selection: <SELECT> |
1780 |
|
1781 |
The <SELECT> element constrains the form field to an |
1782 |
enumerated list of values. The values are given in <OPTION> |
1783 |
elements. Attributes are: |
1784 |
|
1785 |
MULTIPLE |
1786 |
indicates that more than one option may be |
1787 |
included in the value. |
1788 |
|
1789 |
NAME |
1790 |
specifies the name of the form field. |
1791 |
|
1792 |
SIZE |
1793 |
specifies the number of visible items. Select |
1794 |
fields of size one are typically pop-down menus, |
1795 |
whereas select fields with size greater than one |
1796 |
are typically lists. |
1797 |
|
1798 |
For example: |
1799 |
|
1800 |
<SELECT NAME="flavor"> |
1801 |
<OPTION>Vanilla |
1802 |
<OPTION>Strawberry |
1803 |
<OPTION>Rum and Raisin |
1804 |
<OPTION>Peach and Orange |
1805 |
</SELECT> |
1806 |
|
1807 |
The initial state has the first option selected, unless a |
1808 |
SELECTED attribute is present on any of the <OPTION> |
1809 |
elements. |
1810 |
|
1811 |
|
1812 |
7.1.3.1. Option: <OPTION> |
1813 |
|
1814 |
The Option element can only occur within a Select element. |
1815 |
It represents one choice, and has the following attributes: |
1816 |
|
1817 |
SELECTED |
1818 |
Indicates that this option is initially selected. |
1819 |
|
1820 |
VALUE |
1821 |
indicates the value to be returned if this option |
1822 |
is chosen. The field value defaults to the content |
1823 |
of the <OPTION> element. |
1824 |
|
1825 |
The content of the <OPTION> element is presented to the user |
1826 |
to represent the option. It is used as a returned value if |
1827 |
the VALUE attribute is not present. |
1828 |
|
1829 |
|
1830 |
7.1.4. Text Area: <TEXTAREA> |
1831 |
|
1832 |
The <TEXTAREA> element represents a multi-line text field. |
1833 |
For example: |
1834 |
|
1835 |
<TEXTAREA NAME="address" ROWS=64 COLS=6> |
1836 |
HaL Computer Systems |
1837 |
1315 Dell Avenue |
1838 |
Campbell, California 95008 |
1839 |
</TEXTAREA> |
1840 |
|
1841 |
The content of the <TEXTAREA> element is the field's initial |
1842 |
value. |
1843 |
|
1844 |
Typically, the ROWS and COLS attributes determine the |
1845 |
visible dimension of the field in characters. The field is |
1846 |
rendered in a fixed-width font. HTML user agents should |
1847 |
allow text to extend beyond these limits by scrolling as |
1848 |
needed. |
1849 |
|
1850 |
|
1851 |
7.2. Form Submission |
1852 |
|
1853 |
An HTML user agent begins processing a form by presenting |
1854 |
the document with the fields in their initial state. The |
1855 |
user is allowed to modify the fields, constrained by the |
1856 |
field type etc. When the user indicates that the form should |
1857 |
be submitted (using a submit button or image input), the |
1858 |
form data set is processed according to its method, action |
1859 |
URI and enctype. |
1860 |
|
1861 |
When there is only one single-line text input field in a |
1862 |
form, the user agent should accept Enter in that field as a |
1863 |
request to submit the form. |
1864 |
|
1865 |
|
1866 |
7.2.1. The `application/x-www-form-urlencoded' Media Type |
1867 |
|
1868 |
The default encoding for all forms is |
1869 |
`application/x-www-form-urlencoded'. A form data set is |
1870 |
represented in this media type as follows: |
1871 |
|
1872 |
1. The form field names and values are escaped: space |
1873 |
characterss are replaced by `+', and then reserved |
1874 |
characters are escaped as per [URL]; that is, |
1875 |
non-alphanumeric characters are replaced by `%HH', a |
1876 |
percent sign and two hexadecimal digits representing |
1877 |
the ASCII code of the character. Line breaks, as in |
1878 |
multi-line textfield values, are represented as CR LF |
1879 |
pairs, i.e. `%0D0A'. |
1880 |
|
1881 |
2. The fields are listed in the order they appear in |
1882 |
the document with the name separated from the value by |
1883 |
`=' and the pairs separated from each other by `&'. |
1884 |
Fields with null values may be omitted. In particular, |
1885 |
unselected radio buttons and checkboxes should not |
1886 |
appear in the encoded data, but hidden fields with |
1887 |
VALUE attributes present should. |
1888 |
|
1889 |
NOTE - The URI from a query form submission can be used |
1890 |
in a normal anchor style hyperlink. Unfortunately, the |
1891 |
use of the `&' character to separate form fields |
1892 |
interacts with its use in SGML attribute values as an |
1893 |
entity reference delimiter. For example, the URI |
1894 |
`http://host/?x=1&y=2' must be written `<a |
1895 |
href="http://host/?x=1&y=2"' or `<a |
1896 |
href="http://host/?x=1&#amp;y=2">'. |
1897 |
HTTP server implementors, and in particular, CGI |
1898 |
implementors are encouraged to support the use of `;' |
1899 |
in place of `&' to save users the trouble of escaping |
1900 |
`&' characters this way. |
1901 |
|
1902 |
|
1903 |
7.2.2. Query Forms: `METHOD=GET' |
1904 |
|
1905 |
If the processing of a form is idempotent (i.e. it has no |
1906 |
lasting observable effect on the state of the world), then |
1907 |
the form method should be `GET'. Many database searches have |
1908 |
no visible side-effects and make ideal applications of query |
1909 |
forms. |
1910 |
|
1911 |
To process a form whose action URL is an HTTP URL and whose |
1912 |
method is `GET', the user agent starts with the action URI |
1913 |
and appends a `?' and the form data set, in |
1914 |
`application/x-www-form-urlencoded' format as above. The |
1915 |
user agent then traverses the link to this URI just as if it |
1916 |
were an anchor (see 6.2, "Traversing Hyperlinks"). |
1917 |
|
1918 |
NOTE - The URL encoding may result in vary long URIs, |
1919 |
which cause some historical HTTP server implementations |
1920 |
to exhibit defective behavior. As a result, some HTML |
1921 |
forms are written using `METHOD=POST' even though the |
1922 |
form submission has no side-effects. |
1923 |
|
1924 |
|
1925 |
7.2.3. Forms with Side-Effects: `METHOD=POST' |
1926 |
|
1927 |
If the service associated with the processing of a form has |
1928 |
side effects (for example, modification of a database or |
1929 |
subscription to a service), the method should be `POST'. |
1930 |
|
1931 |
To process a form whose action URL is an HTTP URL and whose |
1932 |
method is `POST', the user agent conducts an HTTP POST |
1933 |
transaction using the action URI, and a message body of type |
1934 |
`application/x-www-form-urlencoded' format as above. The |
1935 |
user agent should display the response from the HTTP POST |
1936 |
interaction just as it would display the response from an |
1937 |
HTTP GET above. |
1938 |
|
1939 |
|
1940 |
7.2.4. Example Form Submission: Questionnaire Form |
1941 |
|
1942 |
Consider the following document: |
1943 |
|
1944 |
<title>Sample of HTML Form Submission</title> |
1945 |
<H1>Sample Questionnaire</H1> |
1946 |
<P>Please fill out this questionnaire: |
1947 |
<FORM METHOD="POST" ACTION="http://www.w3.org/sample"> |
1948 |
<P>Your name: <INPUT NAME="name" size="48"> |
1949 |
<P>Male <INPUT NAME="gender" TYPE=RADIO VALUE="male"> |
1950 |
<P>Female <INPUT NAME="gender" TYPE=RADIO VALUE="female"> |
1951 |
<P>Number in family: <INPUT NAME="family" TYPE=text> |
1952 |
<P>Cities in which you maintain a residence: |
1953 |
<UL> |
1954 |
<LI>Kent <INPUT NAME="city" TYPE=checkbox VALUE="kent"> |
1955 |
<LI>Miami <INPUT NAME="city" TYPE=checkbox VALUE="miami"> |
1956 |
<LI>Other <TEXTAREA NAME="other" cols=48 rows=4></textarea> |
1957 |
</UL> |
1958 |
Nickname: <INPUT NAME="nickname" SIZE="42"> |
1959 |
<P>Thank you for responding to this questionnaire. |
1960 |
<P><INPUT TYPE=SUBMIT> <INPUT TYPE=RESET> |
1961 |
</FORM> |
1962 |
|
1963 |
The inital state of the form data set is: |
1964 |
|
1965 |
name |
1966 |
``'' |
1967 |
|
1968 |
gender |
1969 |
``male'' |
1970 |
|
1971 |
family |
1972 |
``'' |
1973 |
|
1974 |
other |
1975 |
``'' |
1976 |
|
1977 |
nickname |
1978 |
``'' |
1979 |
|
1980 |
Note that the radio input has an initial value, while the |
1981 |
checkbox has none. |
1982 |
|
1983 |
The user might edit the fields and request that the form be |
1984 |
submitted. At that point, suppose the values are: |
1985 |
|
1986 |
name |
1987 |
``John Doe'' |
1988 |
|
1989 |
gender |
1990 |
``male'' |
1991 |
|
1992 |
family |
1993 |
``5'' |
1994 |
|
1995 |
city |
1996 |
``kent,miami'' |
1997 |
|
1998 |
other |
1999 |
``abc\ndef'' |
2000 |
|
2001 |
nickname |
2002 |
``J&D'' |
2003 |
|
2004 |
The user agent then conducts an HTTP POST transaction using |
2005 |
the URI `http://www.w3.org/sample'. The message body would |
2006 |
be (ignore the linebreak): |
2007 |
|
2008 |
name=John+Doe&gender=male&family=5&city=kent%2Cmiami& |
2009 |
other=abc%0D0Adef&nickname=J%26D |
2010 |
|
2011 |
|
2012 |
8. HTML Public Text |
2013 |
|
2014 |
|
2015 |
8.1. HTML DTD |
2016 |
|
2017 |
This is the Document Type Definition for the HyperText |
2018 |
Markup Language. |
2019 |
|
2020 |
<!-- html.dtd |
2021 |
|
2022 |
Document Type Definition for the HyperText Markup Language |
2023 |
(HTML DTD) |
2024 |
|
2025 |
$Id: html.dtd,v 1.25 1995/03/29 18:53:13 connolly Exp $ |
2026 |
|
2027 |
Author: Daniel W. Connolly <connolly@w3.org> |
2028 |
See Also: html.decl, html-0.dtd, html-1.dtd |
2029 |
http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html |
2030 |
--> |
2031 |
|
2032 |
<!ENTITY % HTML.Version |
2033 |
"-//IETF//DTD HTML 2.0//EN" |
2034 |
|
2035 |
-- Typical usage: |
2036 |
|
2037 |
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> |
2038 |
<html> |
2039 |
... |
2040 |
</html> |
2041 |
-- |
2042 |
> |
2043 |
|
2044 |
|
2045 |
<!--============ Feature Test Entities ========================--> |
2046 |
|
2047 |
<!ENTITY % HTML.Recommended "IGNORE" |
2048 |
-- Certain features of the language are necessary for |
2049 |
compatibility with widespread usage, but they may |
2050 |
compromise the structural integrity of a document. |
2051 |
This feature test entity enables a more prescriptive |
2052 |
document type definition that eliminates |
2053 |
those features. |
2054 |
--> |
2055 |
|
2056 |
<![ %HTML.Recommended [ |
2057 |
<!ENTITY % HTML.Deprecated "IGNORE"> |
2058 |
]]> |
2059 |
|
2060 |
<!ENTITY % HTML.Deprecated "INCLUDE" |
2061 |
-- Certain features of the language are necessary for |
2062 |
compatibility with earlier versions of the specification, |
2063 |
but they tend to be used an implemented inconsistently, |
2064 |
and their use is deprecated. This feature test entity |
2065 |
enables a document type definition that eliminates |
2066 |
these features. |
2067 |
--> |
2068 |
|
2069 |
<!ENTITY % HTML.Highlighting "INCLUDE" |
2070 |
-- Use this feature test entity to validate that a |
2071 |
document uses no highlighting tags, which may be |
2072 |
ignored on minimal implementations. |
2073 |
--> |
2074 |
|
2075 |
<!ENTITY % HTML.Forms "INCLUDE" |
2076 |
-- Use this feature test entity to validate that a document |
2077 |
contains no forms, which may not be supported in minimal |
2078 |
implementations |
2079 |
--> |
2080 |
|
2081 |
<!--============== Imported Names ==============================--> |
2082 |
|
2083 |
<!ENTITY % Content-Type "CDATA" |
2084 |
-- meaning an internet media type |
2085 |
(aka MIME content type, as per RFC1521) |
2086 |
--> |
2087 |
|
2088 |
<!ENTITY % HTTP-Method "GET | POST" |
2089 |
-- as per HTTP specification, in progress |
2090 |
--> |
2091 |
|
2092 |
<!ENTITY % URI "CDATA" |
2093 |
-- The term URI means a CDATA attribute |
2094 |
whose value is a Uniform Resource Identifier, |
2095 |
as defined by |
2096 |
"Universal Resource Identifiers" by Tim Berners-Lee |
2097 |
aka RFC 1630 |
2098 |
|
2099 |
Note that CDATA attributes are limited by the LITLEN |
2100 |
capacity (1024 in the current version of html.decl), |
2101 |
so that URIs in HTML have a bounded length. |
2102 |
|
2103 |
--> |
2104 |
|
2105 |
|
2106 |
<!--========= DTD "Macros" =====================--> |
2107 |
|
2108 |
<!ENTITY % heading "H1|H2|H3|H4|H5|H6"> |
2109 |
|
2110 |
<!ENTITY % list " UL | OL | DIR | MENU " > |
2111 |
|
2112 |
|
2113 |
<!--======= Character mnemonic entities =================--> |
2114 |
|
2115 |
<!ENTITY % ISOlat1 PUBLIC |
2116 |
"ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML"> |
2117 |
%ISOlat1; |
2118 |
|
2119 |
<!ENTITY amp CDATA "&" -- ampersand --> |
2120 |
<!ENTITY gt CDATA ">" -- greater than --> |
2121 |
<!ENTITY lt CDATA "<" -- less than --> |
2122 |
<!ENTITY quot CDATA """ -- double quote --> |
2123 |
|
2124 |
|
2125 |
<!--========= SGML Document Access (SDA) Parameter Entities =====--> |
2126 |
|
2127 |
<!-- HTML 2.0 contains SGML Document Access (SDA) fixed attributes |
2128 |
in support of easy transformation to the International Committee |
2129 |
for Accessible Document Design (ICADD) DTD |
2130 |
"-//EC-USA-CDA/ICADD//DTD ICADD22//EN". |
2131 |
ICADD applications are designed to support usable access to |
2132 |
structured information by print-impaired individuals through |
2133 |
Braille, large print and voice synthesis. For more information on |
2134 |
SDA & ICADD: |
2135 |
- ISO 12083:1993, Annex A.8, Facilities for Braille, |
2136 |
large print and computer voice |
2137 |
- ICADD ListServ |
2138 |
<ICADD%ASUACAD.BITNET@ARIZVM1.ccit.arizona.edu> |
2139 |
- Usenet news group bit.listserv.easi |
2140 |
- Recording for the Blind, +1 800 221 4792 |
2141 |
--> |
2142 |
|
2143 |
<!ENTITY % SDAFORM "SDAFORM CDATA #FIXED" |
2144 |
-- one to one mapping --> |
2145 |
<!ENTITY % SDARULE "SDARULE CDATA #FIXED" |
2146 |
-- context-sensitive mapping --> |
2147 |
<!ENTITY % SDAPREF "SDAPREF CDATA #FIXED" |
2148 |
-- generated text prefix --> |
2149 |
<!ENTITY % SDASUFF "SDASUFF CDATA #FIXED" |
2150 |
-- generated text suffix --> |
2151 |
<!ENTITY % SDASUSP "SDASUSP NAME #FIXED" |
2152 |
-- suspend transform process --> |
2153 |
|
2154 |
|
2155 |
<!--========== Text Markup =====================--> |
2156 |
|
2157 |
<![ %HTML.Highlighting [ |
2158 |
|
2159 |
<!ENTITY % font " TT | B | I "> |
2160 |
|
2161 |
<!ENTITY % phrase "EM | STRONG | CODE | SAMP | KBD | VAR | CITE "> |
2162 |
|
2163 |
<!ENTITY % text "#PCDATA | A | IMG | BR | %phrase | %font"> |
2164 |
|
2165 |
<!ELEMENT (%font;|%phrase) - - (%text)*> |
2166 |
<!ATTLIST ( TT | CODE | SAMP | KBD | VAR ) |
2167 |
%SDAFORM; "Lit" |
2168 |
> |
2169 |
<!ATTLIST ( B | STRONG ) |
2170 |
%SDAFORM; "B" |
2171 |
> |
2172 |
<!ATTLIST ( I | EM | CITE ) |
2173 |
%SDAFORM; "It" |
2174 |
> |
2175 |
|
2176 |
<!-- <TT> Typewriter text --> |
2177 |
<!-- <B> Bold text --> |
2178 |
<!-- <I> Italic text --> |
2179 |
|
2180 |
<!-- <EM> Emphasized phrase --> |
2181 |
<!-- <STRONG> Strong emphais --> |
2182 |
<!-- <CODE> Source code phrase --> |
2183 |
<!-- <SAMP> Sample text or characters --> |
2184 |
<!-- <KBD> Keyboard phrase, e.g. user input --> |
2185 |
<!-- <VAR> Variable phrase or substituable --> |
2186 |
<!-- <CITE> Name or title of cited work --> |
2187 |
|
2188 |
<!ENTITY % pre.content "#PCDATA | A | HR | BR | %font | %phrase"> |
2189 |
|
2190 |
]]> |
2191 |
|
2192 |
<!ENTITY % text "#PCDATA | A | IMG | BR"> |
2193 |
|
2194 |
<!ELEMENT BR - O EMPTY> |
2195 |
<!ATTLIST BR |
2196 |
%SDAPREF; "&#RE;" |
2197 |
> |
2198 |
|
2199 |
<!-- <BR> Line break --> |
2200 |
|
2201 |
|
2202 |
<!--========= Link Markup ======================--> |
2203 |
|
2204 |
<![ %HTML.Recommended [ |
2205 |
<!ENTITY % linkName "ID"> |
2206 |
]]> |
2207 |
|
2208 |
<!ENTITY % linkName "CDATA"> |
2209 |
|
2210 |
<!ENTITY % linkType "NAME" |
2211 |
-- a list of these will be specified at a later date --> |
2212 |
|
2213 |
<!ENTITY % linkExtraAttributes |
2214 |
"REL %linkType #IMPLIED |
2215 |
REV %linkType #IMPLIED |
2216 |
URN CDATA #IMPLIED |
2217 |
TITLE CDATA #IMPLIED |
2218 |
METHODS NAMES #IMPLIED |
2219 |
"> |
2220 |
|
2221 |
<![ %HTML.Recommended [ |
2222 |
<!ENTITY % A.content "(%text)*" |
2223 |
-- <H1><a name="xxx">Heading</a></H1> |
2224 |
is preferred to |
2225 |
<a name="xxx"><H1>Heading</H1></a> |
2226 |
--> |
2227 |
]]> |
2228 |
|
2229 |
<!ENTITY % A.content "(%heading|%text)*"> |
2230 |
|
2231 |
<!ELEMENT A - - %A.content -(A)> |
2232 |
<!ATTLIST A |
2233 |
HREF %URI #IMPLIED |
2234 |
NAME %linkName #IMPLIED |
2235 |
%linkExtraAttributes; |
2236 |
%SDAPREF; "<Anchor: #AttList>" |
2237 |
> |
2238 |
<!-- <A> Anchor; source/destination of link --> |
2239 |
<!-- <A NAME="..."> Name of this anchor --> |
2240 |
<!-- <A HREF="..."> Address of link destination --> |
2241 |
<!-- <A URN="..."> Permanent address of destination --> |
2242 |
<!-- <A REL=...> Relationship to destination --> |
2243 |
<!-- <A REV=...> Relationship of destination to this --> |
2244 |
<!-- <A TITLE="..."> Title of destination (advisory) --> |
2245 |
<!-- <A METHODS="..."> Operations on destination (advisory) --> |
2246 |
|
2247 |
|
2248 |
<!--========== Images ==========================--> |
2249 |
|
2250 |
<!ELEMENT IMG - O EMPTY> |
2251 |
<!ATTLIST IMG |
2252 |
SRC %URI; #REQUIRED |
2253 |
ALT CDATA #IMPLIED |
2254 |
ALIGN (top|middle|bottom) #IMPLIED |
2255 |
ISMAP (ISMAP) #IMPLIED |
2256 |
%SDAPREF; "<Fig><?SDATrans Img: #AttList>#AttVal(Alt)</Fig>" |
2257 |
> |
2258 |
|
2259 |
<!-- <IMG> Image; icon, glyph or illustration --> |
2260 |
<!-- <IMG SRC="..."> Address of image object --> |
2261 |
<!-- <IMG ALT="..."> Textual alternative --> |
2262 |
<!-- <IMG ALIGN=...> Position relative to text --> |
2263 |
<!-- <IMG ISMAP> Each pixel can be a link --> |
2264 |
|
2265 |
<!--========== Paragraphs=======================--> |
2266 |
|
2267 |
<!ELEMENT P - O (%text)*> |
2268 |
<!ATTLIST P |
2269 |
%SDAFORM; "Para" |
2270 |
> |
2271 |
|
2272 |
<!-- <P> Paragraph --> |
2273 |
|
2274 |
|
2275 |
<!--========== Headings, Titles, Sections ===============--> |
2276 |
|
2277 |
<!ELEMENT HR - O EMPTY> |
2278 |
<!ATTLIST HR |
2279 |
%SDAPREF; "&#RE;&#RE;" |
2280 |
> |
2281 |
|
2282 |
<!-- <HR> Horizontal rule --> |
2283 |
|
2284 |
<!ELEMENT ( %heading ) - - (%text;)*> |
2285 |
<!ATTLIST H1 |
2286 |
%SDAFORM; "H1" |
2287 |
> |
2288 |
<!ATTLIST H2 |
2289 |
%SDAFORM; "H2" |
2290 |
> |
2291 |
<!ATTLIST H3 |
2292 |
%SDAFORM; "H3" |
2293 |
> |
2294 |
<!ATTLIST H4 |
2295 |
%SDAFORM; "H4" |
2296 |
> |
2297 |
<!ATTLIST H5 |
2298 |
%SDAFORM; "H5" |
2299 |
> |
2300 |
<!ATTLIST H6 |
2301 |
%SDAFORM; "H6" |
2302 |
> |
2303 |
|
2304 |
<!-- <H1> Heading, level 1 --> |
2305 |
<!-- <H2> Heading, level 2 --> |
2306 |
<!-- <H3> Heading, level 3 --> |
2307 |
<!-- <H4> Heading, level 4 --> |
2308 |
<!-- <H5> Heading, level 5 --> |
2309 |
<!-- <H6> Heading, level 6 --> |
2310 |
|
2311 |
|
2312 |
<!--========== Text Flows ======================--> |
2313 |
|
2314 |
<![ %HTML.Forms [ |
2315 |
<!ENTITY % block.forms "BLOCKQUOTE | FORM | ISINDEX"> |
2316 |
]]> |
2317 |
|
2318 |
<!ENTITY % block.forms "BLOCKQUOTE"> |
2319 |
|
2320 |
<![ %HTML.Deprecated [ |
2321 |
<!ENTITY % preformatted "PRE | XMP | LISTING"> |
2322 |
]]> |
2323 |
|
2324 |
<!ENTITY % preformatted "PRE"> |
2325 |
|
2326 |
<!ENTITY % block "P | %list | DL |
2327 |
| %preformatted |
2328 |
| %block.forms"> |
2329 |
|
2330 |
<!ENTITY % flow "(%text|%block)*"> |
2331 |
|
2332 |
<!ENTITY % pre.content "#PCDATA | A | HR | BR"> |
2333 |
<!ELEMENT PRE - - (%pre.content)*> |
2334 |
<!ATTLIST PRE |
2335 |
WIDTH NUMBER #implied |
2336 |
%SDAFORM; "Lit" |
2337 |
> |
2338 |
|
2339 |
<!-- <PRE> Preformatted text --> |
2340 |
<!-- <PRE WIDTH=...> Maximum characters per line --> |
2341 |
|
2342 |
<![ %HTML.Deprecated [ |
2343 |
|
2344 |
<!ENTITY % literal "CDATA" |
2345 |
-- historical, non-conforming parsing mode where |
2346 |
the only markup signal is the end tag |
2347 |
in full |
2348 |
--> |
2349 |
|
2350 |
<!ELEMENT (XMP|LISTING) - - %literal> |
2351 |
<!ATTLIST XMP |
2352 |
%SDAFORM; "Lit" |
2353 |
%SDAPREF; "Example:&#RE;" |
2354 |
> |
2355 |
<!ATTLIST LISTING |
2356 |
%SDAFORM; "Lit" |
2357 |
%SDAPREF; "Listing:&#RE;" |
2358 |
> |
2359 |
|
2360 |
<!-- <XMP> Example section --> |
2361 |
<!-- <LISTING> Computer listing --> |
2362 |
|
2363 |
<!ELEMENT PLAINTEXT - O %literal> |
2364 |
<!-- <PLAINTEXT> Plain text passage --> |
2365 |
|
2366 |
<!ATTLIST PLAINTEXT |
2367 |
%SDAFORM; "Lit" |
2368 |
> |
2369 |
]]> |
2370 |
|
2371 |
|
2372 |
<!--========== Lists ==================--> |
2373 |
|
2374 |
<!ELEMENT DL - - (DT | DD)+> |
2375 |
<!ATTLIST DL |
2376 |
COMPACT (COMPACT) #IMPLIED |
2377 |
%SDAFORM; "List" |
2378 |
%SDAPREF; "Definition List:" |
2379 |
> |
2380 |
|
2381 |
<!ELEMENT DT - O (%text)*> |
2382 |
<!ATTLIST DT |
2383 |
%SDAFORM; "Term" |
2384 |
> |
2385 |
|
2386 |
<!ELEMENT DD - O %flow> |
2387 |
<!ATTLIST DD |
2388 |
%SDAFORM; "LItem" |
2389 |
> |
2390 |
|
2391 |
<!-- <DL> Definition list, or glossary --> |
2392 |
<!-- <DL COMPACT> Compact style list --> |
2393 |
<!-- <DT> Term in definition list --> |
2394 |
<!-- <DD> Definition of term --> |
2395 |
|
2396 |
<!ELEMENT (OL|UL) - - (LI)+> |
2397 |
<!ATTLIST OL |
2398 |
COMPACT (COMPACT) #IMPLIED |
2399 |
%SDAFORM; "List" |
2400 |
> |
2401 |
<!ATTLIST UL |
2402 |
COMPACT (COMPACT) #IMPLIED |
2403 |
%SDAFORM; "List" |
2404 |
> |
2405 |
<!-- <UL> Unordered list --> |
2406 |
<!-- <UL COMPACT> Compact list style --> |
2407 |
<!-- <OL> Ordered, or numbered list --> |
2408 |
<!-- <OL COMPACT> Compact list style --> |
2409 |
|
2410 |
|
2411 |
<!ELEMENT (DIR|MENU) - - (LI)+ -(%block)> |
2412 |
<!ATTLIST DIR |
2413 |
COMPACT (COMPACT) #IMPLIED |
2414 |
%SDAFORM; "List" |
2415 |
%SDAPREF; "<LHead>Directory</LHead>" |
2416 |
> |
2417 |
<!ATTLIST MENU |
2418 |
COMPACT (COMPACT) #IMPLIED |
2419 |
%SDAFORM; "List" |
2420 |
%SDAPREF; "<LHead>Menu</LHead>" |
2421 |
> |
2422 |
|
2423 |
<!-- <DIR> Directory list --> |
2424 |
<!-- <DIR COMPACT> Compact list style --> |
2425 |
<!-- <MENU> Menu list --> |
2426 |
<!-- <MENU COMPACT> Compact list style --> |
2427 |
|
2428 |
<!ELEMENT LI - O %flow> |
2429 |
<!ATTLIST LI |
2430 |
%SDAFORM; "LItem" |
2431 |
> |
2432 |
|
2433 |
<!-- <LI> List item --> |
2434 |
|
2435 |
<!--========== Document Body ===================--> |
2436 |
|
2437 |
<![ %HTML.Recommended [ |
2438 |
<!ENTITY % body.content "(%heading|%block|HR|ADDRESS|IMG)*" |
2439 |
-- <h1>Heading</h1> |
2440 |
<p>Text ... |
2441 |
is preferred to |
2442 |
<h1>Heading</h1> |
2443 |
Text ... |
2444 |
--> |
2445 |
]]> |
2446 |
|
2447 |
<!ENTITY % body.content "(%heading | %text | %block | |
2448 |
HR | ADDRESS)*"> |
2449 |
|
2450 |
<!ELEMENT BODY O O %body.content> |
2451 |
|
2452 |
<!-- <BODY> Document body --> |
2453 |
|
2454 |
<!ELEMENT BLOCKQUOTE - - %body.content> |
2455 |
<!ATTLIST BLOCKQUOTE |
2456 |
%SDAFORM; "BQ" |
2457 |
> |
2458 |
|
2459 |
<!-- <BLOCKQUOTE> Quoted passage --> |
2460 |
|
2461 |
<!ELEMENT ADDRESS - - (%text|P)*> |
2462 |
<!ATTLIST ADDRESS |
2463 |
%SDAFORM; "Lit" |
2464 |
%SDAPREF; "Address:&#RE;" |
2465 |
> |
2466 |
|
2467 |
<!-- <ADDRESS> Address, signature, or byline --> |
2468 |
|
2469 |
|
2470 |
<!--======= Forms ====================--> |
2471 |
|
2472 |
<![ %HTML.Forms [ |
2473 |
|
2474 |
<!ELEMENT FORM - - %body.content -(FORM) +(INPUT|SELECT|TEXTAREA)> |
2475 |
<!ATTLIST FORM |
2476 |
ACTION %URI #IMPLIED |
2477 |
METHOD (%HTTP-Method) GET |
2478 |
ENCTYPE %Content-Type; "application/x-www-form-urlencoded" |
2479 |
%SDAPREF; "<Para>Form:</Para>" |
2480 |
%SDASUFF; "<Para>Form End.</Para>" |
2481 |
> |
2482 |
|
2483 |
<!-- <FORM> Fill-out or data-entry form --> |
2484 |
<!-- <FORM ACTION="..."> Address for completed form --> |
2485 |
<!-- <FORM METHOD=...> Method of submitting form --> |
2486 |
<!-- <FORM ENCTYPE="..."> Representation of form data --> |
2487 |
|
2488 |
<!ENTITY % InputType "(TEXT | PASSWORD | CHECKBOX | |
2489 |
RADIO | SUBMIT | RESET | |
2490 |
IMAGE | HIDDEN )"> |
2491 |
<!ELEMENT INPUT - O EMPTY> |
2492 |
<!ATTLIST INPUT |
2493 |
TYPE %InputType TEXT |
2494 |
NAME CDATA #IMPLIED |
2495 |
VALUE CDATA #IMPLIED |
2496 |
SRC %URI #IMPLIED |
2497 |
CHECKED (CHECKED) #IMPLIED |
2498 |
SIZE CDATA #IMPLIED |
2499 |
MAXLENGTH NUMBER #IMPLIED |
2500 |
ALIGN (top|middle|bottom) #IMPLIED |
2501 |
%SDAPREF; "Input: " |
2502 |
> |
2503 |
|
2504 |
<!-- <INPUT> Form input datum --> |
2505 |
<!-- <INPUT TYPE=...> Type of input interaction --> |
2506 |
<!-- <INPUT NAME=...> Name of form datum --> |
2507 |
<!-- <INPUT VALUE="..."> Default/initial/selected value --> |
2508 |
<!-- <INPUT SRC="..."> Address of image --> |
2509 |
<!-- <INPUT CHECKED> Initial state is "on" --> |
2510 |
<!-- <INPUT SIZE=...> Field size hint --> |
2511 |
<!-- <INPUT MAXLENGTH=...> Data length maximum --> |
2512 |
<!-- <INPUT ALIGN=...> Image alignment --> |
2513 |
|
2514 |
<!ELEMENT SELECT - - (OPTION+) -(INPUT|SELECT|TEXTAREA)> |
2515 |
<!ATTLIST SELECT |
2516 |
NAME CDATA #REQUIRED |
2517 |
SIZE NUMBER #IMPLIED |
2518 |
MULTIPLE (MULTIPLE) #IMPLIED |
2519 |
%SDAFORM; "List" |
2520 |
%SDAPREF; |
2521 |
"<LHead>Select #AttVal(Multiple)</LHead>" |
2522 |
> |
2523 |
|
2524 |
<!-- <SELECT> Selection of option(s) --> |
2525 |
<!-- <SELECT NAME=...> Name of form datum --> |
2526 |
<!-- <SELECT SIZE=...> Options displayed at a time --> |
2527 |
<!-- <SELECT MULTIPLE> Multiple selections allowed --> |
2528 |
|
2529 |
<!ELEMENT OPTION - O (#PCDATA)*> |
2530 |
<!ATTLIST OPTION |
2531 |
SELECTED (SELECTED) #IMPLIED |
2532 |
VALUE CDATA #IMPLIED |
2533 |
%SDAFORM; "LItem" |
2534 |
%SDAPREF; |
2535 |
"Option: #AttVal(Value) #AttVal(Selected)" |
2536 |
> |
2537 |
|
2538 |
<!-- <OPTION> A selection option --> |
2539 |
<!-- <OPTION SELECTED> Initial state --> |
2540 |
<!-- <OPTION VALUE="..."> Form datum value for this option--> |
2541 |
|
2542 |
<!ELEMENT TEXTAREA - - (#PCDATA)* -(INPUT|SELECT|TEXTAREA)> |
2543 |
<!ATTLIST TEXTAREA |
2544 |
NAME CDATA #REQUIRED |
2545 |
ROWS NUMBER #REQUIRED |
2546 |
COLS NUMBER #REQUIRED |
2547 |
%SDAFORM; "Para" |
2548 |
%SDAPREF; "Input Text -- #AttVal(Name): " |
2549 |
> |
2550 |
|
2551 |
<!-- <TEXTAREA> An area for text input --> |
2552 |
<!-- <TEXTAREA NAME=...> Name of form datum --> |
2553 |
<!-- <TEXTAREA ROWS=...> Height of area --> |
2554 |
<!-- <TEXTAREA COLS=...> Width of area --> |
2555 |
|
2556 |
]]> |
2557 |
|
2558 |
|
2559 |
<!--======= Document Head ======================--> |
2560 |
|
2561 |
<![ %HTML.Recommended [ |
2562 |
<!ENTITY % head.extra "META* & LINK*"> |
2563 |
]]> |
2564 |
|
2565 |
<!ENTITY % head.extra "NEXTID? & META* & LINK*"> |
2566 |
|
2567 |
<!ENTITY % head.content "TITLE & ISINDEX? & BASE? & |
2568 |
(%head.extra)"> |
2569 |
|
2570 |
<!ELEMENT HEAD O O (%head.content)> |
2571 |
|
2572 |
<!-- <HEAD> Document head --> |
2573 |
|
2574 |
<!ELEMENT TITLE - - (#PCDATA)*> |
2575 |
<!ATTLIST TITLE |
2576 |
%SDAFORM; "Ti" > |
2577 |
|
2578 |
<!-- <TITLE> Title of document --> |
2579 |
|
2580 |
<!ELEMENT LINK - O EMPTY> |
2581 |
<!ATTLIST LINK |
2582 |
HREF %URI #REQUIRED |
2583 |
%linkExtraAttributes; |
2584 |
%SDAPREF; "Linked to : #AttVal (TITLE) (URN) (HREF)>" > |
2585 |
|
2586 |
<!-- <LINK> Link from this document --> |
2587 |
<!-- <LINK HREF="..."> Address of link destination --> |
2588 |
<!-- <LINK URN="..."> Lasting name of destination --> |
2589 |
<!-- <LINK REL=...> Relationship to destination --> |
2590 |
<!-- <LINK REV=...> Relationship of destination to this --> |
2591 |
<!-- <LINK TITLE="..."> Title of destination (advisory) --> |
2592 |
<!-- <LINK METHODS="..."> Operations allowed (advisory) --> |
2593 |
|
2594 |
<!ELEMENT ISINDEX - O EMPTY> |
2595 |
<!ATTLIST ISINDEX |
2596 |
%SDAPREF; |
2597 |
"<Para>[Document is indexed/searchable.]</Para>"> |
2598 |
|
2599 |
<!-- <ISINDEX> Document is a searchable index --> |
2600 |
|
2601 |
<!ELEMENT BASE - O EMPTY> |
2602 |
<!ATTLIST BASE |
2603 |
HREF %URI; #REQUIRED > |
2604 |
|
2605 |
<!-- <BASE> Base context document --> |
2606 |
<!-- <BASE HREF="..."> Address for this document --> |
2607 |
|
2608 |
<!ELEMENT NEXTID - O EMPTY> |
2609 |
<!ATTLIST NEXTID |
2610 |
N %linkName #REQUIRED > |
2611 |
|
2612 |
<!-- <NEXTID> Next ID to use for link name --> |
2613 |
<!-- <NEXTID N=...> Next ID to use for link name --> |
2614 |
|
2615 |
<!ELEMENT META - O EMPTY> |
2616 |
<!ATTLIST META |
2617 |
HTTP-EQUIV NAME #IMPLIED |
2618 |
NAME NAME #IMPLIED |
2619 |
CONTENT CDATA #REQUIRED > |
2620 |
|
2621 |
<!-- <META> Generic Metainformation --> |
2622 |
<!-- <META HTTP-EQUIV=...> HTTP response header name --> |
2623 |
<!-- <META NAME=...> Metainformation name --> |
2624 |
<!-- <META CONTENT="..."> Associated information --> |
2625 |
|
2626 |
<!--======= Document Structure =================--> |
2627 |
|
2628 |
<![ %HTML.Deprecated [ |
2629 |
<!ENTITY % html.content "HEAD, BODY, PLAINTEXT?"> |
2630 |
]]> |
2631 |
<!ENTITY % html.content "HEAD, BODY"> |
2632 |
|
2633 |
<!ELEMENT HTML O O (%html.content)> |
2634 |
<!ENTITY % version.attr "VERSION CDATA #FIXED '%HTML.Version;'"> |
2635 |
|
2636 |
<!ATTLIST HTML |
2637 |
%version.attr; |
2638 |
%SDAFORM; "Book" |
2639 |
> |
2640 |
|
2641 |
<!-- <HTML> HTML Document --> |
2642 |
|
2643 |
|
2644 |
8.2. SGML Declaration for HTML |
2645 |
|
2646 |
This is the SGML Declaration for HyperText Markup Language |
2647 |
(HTML) as used by the World Wide Web (WWW) application: |
2648 |
|
2649 |
<!SGML "ISO 8879:1986" |
2650 |
-- |
2651 |
SGML Declaration for HyperText Markup Language (HTML). |
2652 |
|
2653 |
-- |
2654 |
|
2655 |
CHARSET |
2656 |
BASESET "ISO 646:1983//CHARSET |
2657 |
International Reference Version |
2658 |
(IRV)//ESC 2/5 4/0" |
2659 |
DESCSET 0 9 UNUSED |
2660 |
9 2 9 |
2661 |
11 2 UNUSED |
2662 |
13 1 13 |
2663 |
14 18 UNUSED |
2664 |
32 95 32 |
2665 |
127 1 UNUSED |
2666 |
BASESET "ISO Registration Number 100//CHARSET |
2667 |
ECMA-94 Right Part of |
2668 |
Latin Alphabet Nr. 1//ESC 2/13 4/1" |
2669 |
|
2670 |
DESCSET 128 32 UNUSED |
2671 |
160 96 32 |
2672 |
|
2673 |
CAPACITY SGMLREF |
2674 |
TOTALCAP 150000 |
2675 |
GRPCAP 150000 |
2676 |
ENTCAP 150000 |
2677 |
|
2678 |
SCOPE DOCUMENT |
2679 |
SYNTAX |
2680 |
SHUNCHAR CONTROLS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
2681 |
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 127 |
2682 |
BASESET "ISO 646:1983//CHARSET |
2683 |
International Reference Version |
2684 |
(IRV)//ESC 2/5 4/0" |
2685 |
DESCSET 0 128 0 |
2686 |
FUNCTION |
2687 |
RE 13 |
2688 |
RS 10 |
2689 |
SPACE 32 |
2690 |
TAB SEPCHAR 9 |
2691 |
|
2692 |
|
2693 |
NAMING LCNMSTRT "" |
2694 |
UCNMSTRT "" |
2695 |
LCNMCHAR ".-" |
2696 |
UCNMCHAR ".-" |
2697 |
NAMECASE GENERAL YES |
2698 |
ENTITY NO |
2699 |
DELIM GENERAL SGMLREF |
2700 |
SHORTREF SGMLREF |
2701 |
NAMES SGMLREF |
2702 |
QUANTITY SGMLREF |
2703 |
ATTSPLEN 2100 |
2704 |
LITLEN 1024 |
2705 |
NAMELEN 72 -- somewhat arbitrary; taken from |
2706 |
internet line length conventions -- |
2707 |
PILEN 1024 |
2708 |
TAGLEN 2100 |
2709 |
GRPGTCNT 150 |
2710 |
GRPCNT 64 |
2711 |
|
2712 |
FEATURES |
2713 |
MINIMIZE |
2714 |
DATATAG NO |
2715 |
OMITTAG YES |
2716 |
RANK NO |
2717 |
SHORTTAG YES |
2718 |
LINK |
2719 |
SIMPLE NO |
2720 |
IMPLICIT NO |
2721 |
EXPLICIT NO |
2722 |
OTHER |
2723 |
CONCUR NO |
2724 |
SUBDOC NO |
2725 |
FORMAL YES |
2726 |
APPINFO "SDA" -- conforming SGML Document Access application |
2727 |
-- |
2728 |
> |
2729 |
<!-- |
2730 |
$Id: html.decl,v 1.15 1995/05/06 01:44:47 connolly Exp $ |
2731 |
|
2732 |
Author: Daniel W. Connolly <connolly@hal.com> |
2733 |
|
2734 |
See also: http://www.hal.com/%7Econnolly/html-spec |
2735 |
http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html |
2736 |
--> |
2737 |
|
2738 |
|
2739 |
8.3. Sample SGML Open Entity Catalog for HTML |
2740 |
|
2741 |
The SGML standard describes an ``entity manager'' as the |
2742 |
portion or component of an SGML system that maps SGML |
2743 |
entities into the actual storage model (e.g., the file |
2744 |
system). The standard itself does not define a particular |
2745 |
mapping methodology or notation. |
2746 |
|
2747 |
To assist the interoperability among various SGML tools and |
2748 |
systems, the SGML Open consortium has passed a technical |
2749 |
resolution that defines a format for an application- |
2750 |
independent entity catalog that maps external identifiers |
2751 |
and/or entity names to file names. |
2752 |
|
2753 |
Each entry in the catalog associates a storage object |
2754 |
identifier (such as a file name) with information about the |
2755 |
external entity that appears in the SGML document. In |
2756 |
addition to entries that associate public identifiers, a |
2757 |
catalog entry can associate an entity name with a storage |
2758 |
object indentifier. For example, the following are possible |
2759 |
catalog entries: |
2760 |
|
2761 |
-- catalog: SGML Open style entity catalog for HTML -- |
2762 |
-- $Id: catalog,v 1.2 1994/11/30 23:45:18 connolly Exp $ -- |
2763 |
|
2764 |
-- Ways to refer to Level 2: most general to most specific -- |
2765 |
PUBLIC "-//IETF//DTD HTML//EN" html.dtd |
2766 |
PUBLIC "-//IETF//DTD HTML 2.0//EN" html.dtd |
2767 |
PUBLIC "-//IETF//DTD HTML Level 2//EN" html.dtd |
2768 |
PUBLIC "-//IETF//DTD HTML 2.0 Level 2//EN" html.dtd |
2769 |
|
2770 |
-- Ways to refer to Level 1: most general to most specific -- |
2771 |
PUBLIC "-//IETF//DTD HTML Level 1//EN" html-1.dtd |
2772 |
PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN" html-1.dtd |
2773 |
|
2774 |
-- Ways to refer to Level 0: most general to most specific -- |
2775 |
PUBLIC "-//IETF//DTD HTML Level 0//EN" html-0.dtd |
2776 |
PUBLIC "-//IETF//DTD HTML 2.0 Level 0//EN" html-0.dtd |
2777 |
|
2778 |
|
2779 |
-- Ways to refer to Strict Level 2: most general to most specific -- |
2780 |
PUBLIC "-//IETF//DTD HTML Strict//EN" html-s.dtd |
2781 |
PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN" html-s.dtd |
2782 |
PUBLIC "-//IETF//DTD HTML Strict Level 2//EN" html-s.dtd |
2783 |
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 2//EN" html-s.dtd |
2784 |
|
2785 |
-- Ways to refer to Strict Level 1: most general to most specific -- |
2786 |
PUBLIC "-//IETF//DTD HTML Strict Level 1//EN" html-1s.dtd |
2787 |
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 1//EN" html-1s.dtd |
2788 |
|
2789 |
-- Ways to refer to Strict Level 0: most general to most specific -- |
2790 |
PUBLIC "-//IETF//DTD HTML Strict Level 0//EN" html-0s.dtd |
2791 |
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 0//EN" html-0s.dtd |
2792 |
|
2793 |
-- ISO latin 1 entity set for HTML -- |
2794 |
PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML" ISOlat1.sgml |
2795 |
|
2796 |
|
2797 |
8.4. Character Entity Sets |
2798 |
|
2799 |
The HTML DTD defines the following entities. They represent |
2800 |
particular graphic characters which have special meanings in |
2801 |
places in the markup, or may not be part of the character |
2802 |
set available to the writer. |
2803 |
|
2804 |
|
2805 |
8.4.1. Numeric and Special Graphic Entity Set |
2806 |
|
2807 |
The following table lists each of the characters included |
2808 |
from the Numeric and Special Graphic entity set, along with |
2809 |
its name, syntax for use, and description. This list is |
2810 |
derived from `ISO Standard 8879:1986//ENTITIES Numeric and |
2811 |
Special Graphic//EN'. However, HTML does not include for the |
2812 |
entire entity set -- only the entities listed below are |
2813 |
included. |
2814 |
|
2815 |
GLYPH NAME SYNTAX DESCRIPTION |
2816 |
< lt < Less than sign |
2817 |
> gt > Greater than sign |
2818 |
& amp & Ampersand |
2819 |
" quot " Double quote sign |
2820 |
|
2821 |
|
2822 |
8.4.2. ISO Latin 1 Character Entity Set |
2823 |
|
2824 |
The following public text lists each of the characters |
2825 |
specified in the Added Latin 1 entity set, along with its |
2826 |
name, syntax for use, and description. This list is derived |
2827 |
from ISO Standard 8879:1986//ENTITIES Added Latin 1//EN. |
2828 |
HTML includes the entire entity set. |
2829 |
|
2830 |
<!-- (C) International Organization for Standardization 1986 |
2831 |
Permission to copy in any form is granted for use with |
2832 |
conforming SGML systems and applications as defined in |
2833 |
ISO 8879, provided this notice is included in all copies. |
2834 |
--> |
2835 |
<!-- Character entity set. Typical invocation: |
2836 |
<!ENTITY % ISOlat1 PUBLIC |
2837 |
"ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML"> |
2838 |
%ISOlat1; |
2839 |
--> |
2840 |
<!-- Modified for use in HTML |
2841 |
$Id: ISOlat1.sgml,v 1.2 1994/11/30 23:45:12 connolly Exp $ --> |
2842 |
<!ENTITY AElig CDATA "Æ" -- capital AE diphthong (ligature) --> |
2843 |
<!ENTITY Aacute CDATA "Á" -- capital A, acute accent --> |
2844 |
<!ENTITY Acirc CDATA "Â" -- capital A, circumflex accent --> |
2845 |
<!ENTITY Agrave CDATA "À" -- capital A, grave accent --> |
2846 |
<!ENTITY Aring CDATA "Å" -- capital A, ring --> |
2847 |
<!ENTITY Atilde CDATA "Ã" -- capital A, tilde --> |
2848 |
<!ENTITY Auml CDATA "Ä" -- capital A, dieresis or umlaut mark --> |
2849 |
<!ENTITY Ccedil CDATA "Ç" -- capital C, cedilla --> |
2850 |
<!ENTITY ETH CDATA "Ð" -- capital Eth, Icelandic --> |
2851 |
<!ENTITY Eacute CDATA "É" -- capital E, acute accent --> |
2852 |
<!ENTITY Ecirc CDATA "Ê" -- capital E, circumflex accent --> |
2853 |
<!ENTITY Egrave CDATA "È" -- capital E, grave accent --> |
2854 |
<!ENTITY Euml CDATA "Ë" -- capital E, dieresis or umlaut mark --> |
2855 |
<!ENTITY Iacute CDATA "Í" -- capital I, acute accent --> |
2856 |
<!ENTITY Icirc CDATA "Î" -- capital I, circumflex accent --> |
2857 |
<!ENTITY Igrave CDATA "Ì" -- capital I, grave accent --> |
2858 |
<!ENTITY Iuml CDATA "Ï" -- capital I, dieresis or umlaut mark --> |
2859 |
<!ENTITY Ntilde CDATA "Ñ" -- capital N, tilde --> |
2860 |
<!ENTITY Oacute CDATA "Ó" -- capital O, acute accent --> |
2861 |
<!ENTITY Ocirc CDATA "Ô" -- capital O, circumflex accent --> |
2862 |
<!ENTITY Ograve CDATA "Ò" -- capital O, grave accent --> |
2863 |
<!ENTITY Oslash CDATA "Ø" -- capital O, slash --> |
2864 |
<!ENTITY Otilde CDATA "Õ" -- capital O, tilde --> |
2865 |
<!ENTITY Ouml CDATA "Ö" -- capital O, dieresis or umlaut mark --> |
2866 |
<!ENTITY THORN CDATA "Þ" -- capital THORN, Icelandic --> |
2867 |
<!ENTITY Uacute CDATA "Ú" -- capital U, acute accent --> |
2868 |
<!ENTITY Ucirc CDATA "Û" -- capital U, circumflex accent --> |
2869 |
<!ENTITY Ugrave CDATA "Ù" -- capital U, grave accent --> |
2870 |
<!ENTITY Uuml CDATA "Ü" -- capital U, dieresis or umlaut mark --> |
2871 |
<!ENTITY Yacute CDATA "Ý" -- capital Y, acute accent --> |
2872 |
<!ENTITY aacute CDATA "á" -- small a, acute accent --> |
2873 |
<!ENTITY acirc CDATA "â" -- small a, circumflex accent --> |
2874 |
<!ENTITY aelig CDATA "æ" -- small ae diphthong (ligature) --> |
2875 |
<!ENTITY agrave CDATA "à" -- small a, grave accent --> |
2876 |
<!ENTITY aring CDATA "å" -- small a, ring --> |
2877 |
<!ENTITY atilde CDATA "ã" -- small a, tilde --> |
2878 |
<!ENTITY auml CDATA "ä" -- small a, dieresis or umlaut mark --> |
2879 |
<!ENTITY ccedil CDATA "ç" -- small c, cedilla --> |
2880 |
<!ENTITY eacute CDATA "é" -- small e, acute accent --> |
2881 |
<!ENTITY ecirc CDATA "ê" -- small e, circumflex accent --> |
2882 |
<!ENTITY egrave CDATA "è" -- small e, grave accent --> |
2883 |
<!ENTITY eth CDATA "ð" -- small eth, Icelandic --> |
2884 |
<!ENTITY euml CDATA "ë" -- small e, dieresis or umlaut mark --> |
2885 |
<!ENTITY iacute CDATA "í" -- small i, acute accent --> |
2886 |
<!ENTITY icirc CDATA "î" -- small i, circumflex accent --> |
2887 |
<!ENTITY igrave CDATA "ì" -- small i, grave accent --> |
2888 |
<!ENTITY iuml CDATA "ï" -- small i, dieresis or umlaut mark --> |
2889 |
<!ENTITY ntilde CDATA "ñ" -- small n, tilde --> |
2890 |
<!ENTITY oacute CDATA "ó" -- small o, acute accent --> |
2891 |
<!ENTITY ocirc CDATA "ô" -- small o, circumflex accent --> |
2892 |
<!ENTITY ograve CDATA "ò" -- small o, grave accent --> |
2893 |
<!ENTITY oslash CDATA "ø" -- small o, slash --> |
2894 |
<!ENTITY otilde CDATA "õ" -- small o, tilde --> |
2895 |
<!ENTITY ouml CDATA "ö" -- small o, dieresis or umlaut mark --> |
2896 |
<!ENTITY szlig CDATA "ß" -- small sharp s, German (sz ligature) --> |
2897 |
<!ENTITY thorn CDATA "þ" -- small thorn, Icelandic --> |
2898 |
<!ENTITY uacute CDATA "ú" -- small u, acute accent --> |
2899 |
<!ENTITY ucirc CDATA "û" -- small u, circumflex accent --> |
2900 |
<!ENTITY ugrave CDATA "ù" -- small u, grave accent --> |
2901 |
<!ENTITY uuml CDATA "ü" -- small u, dieresis or umlaut mark --> |
2902 |
<!ENTITY yacute CDATA "ý" -- small y, acute accent --> |
2903 |
<!ENTITY yuml CDATA "ÿ" -- small y, dieresis or umlaut mark --> |
2904 |
|
2905 |
|
2906 |
9. Glossary |
2907 |
|
2908 |
absolute URI |
2909 |
a URI in absolute form, as per [URL] |
2910 |
|
2911 |
anchor |
2912 |
a hyperlink navigation option; typically, a |
2913 |
highlighted phrase marked as an <A> element. |
2914 |
|
2915 |
base URI |
2916 |
URI used as the base of an HTML document for the |
2917 |
purpose of resolving hyperlink destinations. |
2918 |
|
2919 |
character |
2920 |
An atom of information, for example a letter or a |
2921 |
digit. Graphic characters have associated glyphs, |
2922 |
where as control characters have associated |
2923 |
processing semantics. |
2924 |
|
2925 |
character |
2926 |
encoding scheme |
2927 |
A function whose domain is the set of sequences of |
2928 |
octets, and whose range is the set of sequences of |
2929 |
characters from a character repertoire; that is, a |
2930 |
sequence of octets and a character encoding scheme |
2931 |
determines a sequence of characters. |
2932 |
|
2933 |
character |
2934 |
repertoire |
2935 |
A finite set of characters; e.g. the range of a |
2936 |
coded character set. |
2937 |
|
2938 |
code position |
2939 |
An integer. A coded character set and a code |
2940 |
position from its domain determine a character. |
2941 |
|
2942 |
coded character |
2943 |
set |
2944 |
A function whose domain is a subset of the |
2945 |
integers and whose range is a character |
2946 |
repertoire. That is, for some set of integers |
2947 |
(usually of the form {0, 1, 2, ..., N} ), a coded |
2948 |
character set and an integer in that set determine |
2949 |
a character. Conversely, a character and a coded |
2950 |
character set determine the character's code |
2951 |
position (or, in rare cases, a few code |
2952 |
positions). |
2953 |
|
2954 |
conforming HTML |
2955 |
user agent |
2956 |
A user agent that conforms to this specification |
2957 |
in its processing of the Internet Media Type |
2958 |
`text/html; version=2.0'. |
2959 |
|
2960 |
data character |
2961 |
Characters other than markup, which make up the |
2962 |
content of elements. |
2963 |
|
2964 |
document |
2965 |
character set |
2966 |
a coded character set whose range includes all |
2967 |
characters used in a document. Every SGML document |
2968 |
has exactly one document character set. Numeric |
2969 |
character references are resolved via the document |
2970 |
character set. |
2971 |
|
2972 |
DTD |
2973 |
document type definition. Rules that apply SGML to |
2974 |
the markup of documents of a particular type, |
2975 |
including a set of element and entity |
2976 |
declarations. [SGML] |
2977 |
|
2978 |
element |
2979 |
A component of the hierarchical structure defined |
2980 |
by a document type definition; it is identified in |
2981 |
a document instance by descriptive markup, sually |
2982 |
a start-tag and end-tag. [SGML] |
2983 |
|
2984 |
end-tag |
2985 |
Descriptive markup that identifies the end of an |
2986 |
element. [SGML] |
2987 |
|
2988 |
entity |
2989 |
data with an associated notation or |
2990 |
interpretation; for example, a sequence of octets |
2991 |
associated with an Internet Media Type.[SGML] |
2992 |
|
2993 |
fragment |
2994 |
identifier |
2995 |
the portion of an HREF attribute value following |
2996 |
the `#' character which modifies the prenentation |
2997 |
of the destination of a hyperlink. |
2998 |
|
2999 |
form data set |
3000 |
a sequence of name/value pairs; the names are |
3001 |
given by an HTML document and the values are given |
3002 |
by a user. |
3003 |
|
3004 |
HTML document |
3005 |
An SGML document conforming to this document type |
3006 |
definition. |
3007 |
|
3008 |
hyperlink |
3009 |
a relationship between to resources, called the |
3010 |
source and the destination. |
3011 |
|
3012 |
markup |
3013 |
Syntactically delimited characters added to the |
3014 |
data of a document to represent its structure. |
3015 |
There are four different kinds of markup: |
3016 |
descriptive markup (tags), references, markup |
3017 |
declarations, and processing instructions.[SGML] |
3018 |
|
3019 |
may |
3020 |
A document or user interface is conforming whether |
3021 |
this statement applies or not. |
3022 |
|
3023 |
media type |
3024 |
an Internet Media Type, as per [IMEDIA]. |
3025 |
|
3026 |
message entity |
3027 |
a head and body. The head is a collection of |
3028 |
name/value fields, and the body is a sequence of |
3029 |
octets. The head defines the content type and |
3030 |
content transfer encoding of the body. [MIME] |
3031 |
|
3032 |
minimally |
3033 |
conforming HTML |
3034 |
user agent |
3035 |
A user agent that conforms to this specification |
3036 |
except for form processing. It may only process |
3037 |
level 1 HTML documents. |
3038 |
|
3039 |
must |
3040 |
Documents or user agents in conflict with this |
3041 |
statement are not conforming. |
3042 |
|
3043 |
SGML document |
3044 |
A sequence of characters organized physically as a |
3045 |
set of entities and logically into a hierarchy of |
3046 |
elements. An SGML document consists of data |
3047 |
characters and markup; the markup describes the |
3048 |
structure of the information and an instance of |
3049 |
that structure.[SGML] |
3050 |
|
3051 |
shall |
3052 |
If a document or user agent conflicts with this |
3053 |
statement, it does not conform to this |
3054 |
specification. |
3055 |
|
3056 |
should |
3057 |
If a document or user agent conflicts with this |
3058 |
statement, undesirable results may occur in |
3059 |
practice even though it conforms to this |
3060 |
specification. |
3061 |
|
3062 |
start-tag |
3063 |
Descriptive markup that identifies the start of an |
3064 |
element and specifies its generic identifier and |
3065 |
attributes. [SGML] |
3066 |
|
3067 |
|
3068 |
syntax-reference |
3069 |
character set |
3070 |
A coded character set whose range includes all |
3071 |
characters used for markup; e.g. name characters |
3072 |
and delimiter characters. |
3073 |
|
3074 |
tag |
3075 |
Markup that delimits an element. A tag includes a |
3076 |
name which refers to an element declaration in the |
3077 |
DTD, and may include attributes.[SGML] |
3078 |
|
3079 |
text entity |
3080 |
A finite sequence of characters. A text entity |
3081 |
typically takes the form of a sequence of octets |
3082 |
with some associated character encoding scheme, |
3083 |
transmitted over the network or stored in a |
3084 |
file.[SGML] |
3085 |
|
3086 |
typical |
3087 |
Typical processing is described for many elements. |
3088 |
This is not a mandatory part of the specification |
3089 |
but is given as guidance for designers and to help |
3090 |
explain the uses for which the elements were |
3091 |
intended. |
3092 |
|
3093 |
URI |
3094 |
A Universal Resource Identifier is a formatted |
3095 |
string that serves as an identifier for a |
3096 |
resource, typcally on the Internet. URIs are used |
3097 |
in HTML to identify the destination of hyperlinks. |
3098 |
URIs in common practice include Uniform Resource |
3099 |
Locators (URLs)[URL] and Relative URLs[RELURL]. |
3100 |
|
3101 |
user agent |
3102 |
A component of a distributed system that presents |
3103 |
an interface and processes requests on behalf of a |
3104 |
user; for example, a www browser or a mail user |
3105 |
agent. |
3106 |
|
3107 |
WWW |
3108 |
The World-Wide Web is a hypertext-based, |
3109 |
distributed information system created by |
3110 |
researchers at CERN in Switzerland. Users may |
3111 |
create, edit or browse hypertext documents. |
3112 |
`http://www.w3.org/' |
3113 |
|
3114 |
|
3115 |
10. Bibliography |
3116 |
|
3117 |
[URI] |
3118 |
T. Berners-Lee. ``Universal Resource Identifiers |
3119 |
in WWW: A Unifying Syntax for the Expression of |
3120 |
Names and Addresses of Objects on the Network as |
3121 |
used in the World- Wide Web.'' RFC 1630, CERN, |
3122 |
June 1994. |
3123 |
|
3124 |
[URL] |
3125 |
T. Berners-Lee, L. Masinter, and M. McCahill. |
3126 |
``Uniform Resource Locators (URL).'' RFC 1738, |
3127 |
CERN, Xerox PARC, University of Minnesota, October |
3128 |
1994. |
3129 |
|
3130 |
[HTTP] |
3131 |
T. Berners-Lee, R. T. Fielding, and H. Frystyk |
3132 |
Nielsen. ``Hypertext Transfer Protocol - |
3133 |
HTTP/1.0.'' Work in Progress |
3134 |
(draft-ietf-http-v10-spec-00.ps), MIT, UC Irvine, |
3135 |
CERN, March 1995. |
3136 |
|
3137 |
[MIME] |
3138 |
N. Borenstein and N. Freed. ``MIME (Multipurpose |
3139 |
Internet Mail Extensions) Part One: Mechanisms for |
3140 |
Specifying and Describing the Format of Internet |
3141 |
Message Bodies.'' RFC 1521, Bellcore, Innosoft, |
3142 |
September 1993. |
3143 |
|
3144 |
[RELURL] |
3145 |
R. T. Fielding. ``Relative Uniform Resource |
3146 |
Locators.'' Work in Progress |
3147 |
(draft-ietf-uri-relative-url-06.txt), UC Irvine, |
3148 |
March 1995. |
3149 |
|
3150 |
[GOLD90] |
3151 |
C. F. Goldfarb. ``The SGML Handbook.'' Y. |
3152 |
Rubinsky, Ed., Oxford University Press, 1990. |
3153 |
|
3154 |
[IMEDIA] |
3155 |
J. Postel. ``Media Type Registration Procedure.'' |
3156 |
RFC 1590, USC/ISI, March 1994. |
3157 |
|
3158 |
[IANA] |
3159 |
J. Reynolds and J. Postel. ``Assigned Numbers.'' |
3160 |
STD 2, RFC 1700, USC/ISI, October 1994. |
3161 |
|
3162 |
[SQ91] |
3163 |
SoftQuad. ``The SGML Primer.'' 3rd ed., SoftQuad |
3164 |
Inc., 1991. |
3165 |
|
3166 |
[US-ASCII] |
3167 |
US-ASCII. Coded Character Set - 7-Bit American |
3168 |
Standard Code for Information Interchange. |
3169 |
Standard ANSI X3.4-1986, ANSI, 1986. |
3170 |
|
3171 |
[ISO-8859-1] |
3172 |
ISO 8859. International Standard -- Information |
3173 |
Processing -- 8-bit Single-Byte Coded Graphic |
3174 |
Character Sets -- Part 1: Latin Alphabet No. 1, |
3175 |
ISO 8859-1:1987. Part 2: Latin alphabet No. 2, ISO |
3176 |
8859-2, 1987. Part 3: Latin alphabet No. 3, ISO |
3177 |
8859-3, 1988. Part 4: Latin alphabet No. 4, ISO |
3178 |
8859-4, 1988. Part 5: Latin/Cyrillic alphabet, ISO |
3179 |
8859-5, 1988. Part 6: Latin/Arabic alphabet, ISO |
3180 |
8859-6, 1987. Part 7: Latin/Greek alphabet, ISO |
3181 |
8859-7, 1987. Part 8: Latin/Hebrew alphabet, ISO |
3182 |
8859-8, 1988. Part 9: Latin alphabet No. 5, ISO |
3183 |
8859-9, 1990. |
3184 |
|
3185 |
[SGML] |
3186 |
ISO 8879. Information Processing - Text and Office |
3187 |
Systems - Standard Generalized Markup Language |
3188 |
(SGML), 1986. |
3189 |
|
3190 |
|
3191 |
11. Appendices |
3192 |
|
3193 |
These appendices are provided for informational reasons only |
3194 |
- they do not form a part of the HTML specification. |
3195 |
|
3196 |
|
3197 |
11.1. The ANSI/ISO 8859-1 Coded Character Set |
3198 |
|
3199 |
This list, sorted numerically, is derived from ANSI/ISO |
3200 |
8859-1 8-bit single-byte coded graphic character set: |
3201 |
|
3202 |
REFERENCE DESCRIPTION |
3203 |
� -  Unused |
3204 |
	 Horizontal tab |
3205 |
Line feed |
3206 |
 -  Unused |
3207 |
  Space |
3208 |
! Exclamation mark |
3209 |
" Quotation mark |
3210 |
# Number sign |
3211 |
$ Dollar sign |
3212 |
% Percent sign |
3213 |
& Ampersand |
3214 |
' Apostrophe |
3215 |
( Left parenthesis |
3216 |
) Right parenthesis |
3217 |
* Asterisk |
3218 |
+ Plus sign |
3219 |
, Comma |
3220 |
- Hyphen |
3221 |
. Period (fullstop) |
3222 |
/ Solidus (slash) |
3223 |
0 - 9 Digits 0-9 |
3224 |
: Colon |
3225 |
; Semi-colon |
3226 |
< Less than |
3227 |
= Equals sign |
3228 |
> Greater than |
3229 |
? Question mark |
3230 |
@ Commercial at |
3231 |
A - Z Letters A-Z |
3232 |
[ Left square bracket |
3233 |
\ Reverse solidus (backslash) |
3234 |
] Right square bracket |
3235 |
^ Caret |
3236 |
_ Horizontal bar (underscore) |
3237 |
` Acute accent |
3238 |
a - z Letters a-z |
3239 |
{ Left curly brace |
3240 |
| Vertical bar |
3241 |
} Right curly brace |
3242 |
~ Tilde |
3243 |
 -   Unused |
3244 |
¡ Inverted exclamation |
3245 |
¢ Cent sign |
3246 |
£ Pound sterling |
3247 |
¤ General currency sign |
3248 |
¥ Yen sign |
3249 |
¦ Broken vertical bar |
3250 |
§ Section sign |
3251 |
¨ Umlaut (dieresis) |
3252 |
© Copyright |
3253 |
ª Feminine ordinal |
3254 |
« Left angle quote, guillemotleft |
3255 |
¬ Not sign |
3256 |
­ Soft hyphen |
3257 |
® Registered trademark |
3258 |
¯ Macron accent |
3259 |
° Degree sign |
3260 |
± Plus or minus |
3261 |
² Superscript two |
3262 |
³ Superscript three |
3263 |
´ Acute accent |
3264 |
µ Micro sign |
3265 |
¶ Paragraph sign |
3266 |
· Middle dot |
3267 |
¸ Cedilla |
3268 |
¹ Superscript one |
3269 |
º Masculine ordinal |
3270 |
» Right angle quote, guillemotright |
3271 |
¼ Fraction one-fourth |
3272 |
½ Fraction one-half |
3273 |
¾ Fraction three-fourths |
3274 |
¿ Inverted question mark |
3275 |
À Capital A, grave accent |
3276 |
Á Capital A, acute accent |
3277 |
 Capital A, circumflex accent |
3278 |
à Capital A, tilde |
3279 |
Ä Capital A, dieresis or umlaut mark |
3280 |
Å Capital A, ring |
3281 |
Æ Capital AE dipthong (ligature) |
3282 |
Ç Capital C, cedilla |
3283 |
È Capital E, grave accent |
3284 |
É Capital E, acute accent |
3285 |
Ê Capital E, circumflex accent |
3286 |
Ë Capital E, dieresis or umlaut mark |
3287 |
Ì Capital I, grave accent |
3288 |
Í Capital I, acute accent |
3289 |
Î Capital I, circumflex accent |
3290 |
Ï Capital I, dieresis or umlaut mark |
3291 |
Ð Capital Eth, Icelandic |
3292 |
Ñ Capital N, tilde |
3293 |
Ò Capital O, grave accent |
3294 |
Ó Capital O, acute accent |
3295 |
Ô Capital O, circumflex accent |
3296 |
Õ Capital O, tilde |
3297 |
Ö Capital O, dieresis or umlaut mark |
3298 |
× Multiply sign |
3299 |
Ø Capital O, slash |
3300 |
Ù Capital U, grave accent |
3301 |
Ú Capital U, acute accent |
3302 |
Û Capital U, circumflex accent |
3303 |
Ü Capital U, dieresis or umlaut mark |
3304 |
Ý Capital Y, acute accent |
3305 |
Þ Capital THORN, Icelandic |
3306 |
ß Small sharp s, German (sz ligature) |
3307 |
à Small a, grave accent |
3308 |
á Small a, acute accent |
3309 |
â Small a, circumflex accent |
3310 |
ã Small a, tilde |
3311 |
ä Small a, dieresis or umlaut mark |
3312 |
å Small a, ring |
3313 |
æ Small ae dipthong (ligature) |
3314 |
ç Small c, cedilla |
3315 |
è Small e, grave accent |
3316 |
é Small e, acute accent |
3317 |
ê Small e, circumflex accent |
3318 |
ë Small e, dieresis or umlaut mark |
3319 |
ì Small i, grave accent |
3320 |
í Small i, acute accent |
3321 |
î Small i, circumflex accent |
3322 |
ï Small i, dieresis or umlaut mark |
3323 |
ð Small eth, Icelandic |
3324 |
ñ Small n, tilde |
3325 |
ò Small o, grave accent |
3326 |
ó Small o, acute accent |
3327 |
ô Small o, circumflex accent |
3328 |
õ Small o, tilde |
3329 |
ö Small o, dieresis or umlaut mark |
3330 |
÷ Division sign |
3331 |
ø Small o, slash |
3332 |
ù Small u, grave accent |
3333 |
ú Small u, acute accent |
3334 |
û Small u, circumflex accent |
3335 |
ü Small u, dieresis or umlaut mark |
3336 |
ý Small y, acute accent |
3337 |
þ Small thorn, Icelandic |
3338 |
ÿ Small y, dieresis or umlaut mark |
3339 |
|
3340 |
|
3341 |
11.2. Obsolete Features |
3342 |
|
3343 |
This section describes elements that are no longer part of |
3344 |
HTML. Client implementors should implement these obsolete |
3345 |
elements for compatibility with previous versions of the |
3346 |
HTML specification. |
3347 |
|
3348 |
|
3349 |
11.2.1. Comment Element |
3350 |
|
3351 |
The Comment element is used to delimit unneeded text and |
3352 |
comments. The Comment element has been introduced in some |
3353 |
HTML applications but should be replaced by the SGML comment |
3354 |
feature in new HTML interpreters (see Section 2.2.5). |
3355 |
|
3356 |
|
3357 |
11.2.2. Highlighted Phrase Element |
3358 |
|
3359 |
<HP> |
3360 |
|
3361 |
The Highlighted Phrase element should be ignored if not |
3362 |
implemented. This element has been replaced by more |
3363 |
meaningful elements (see Section 8). |
3364 |
|
3365 |
Example of use: |
3366 |
|
3367 |
<HP1>first highlighted phrase</HP1>non- |
3368 |
highlighted text<HP2>second highlighted phrase</HP2> etc. |
3369 |
|
3370 |
|
3371 |
11.2.3. Plain Text Element |
3372 |
|
3373 |
<PLAINTEXT> |
3374 |
|
3375 |
The Plain Text element is used to terminates the HTML entity |
3376 |
and to indicate that what follows is not SGML which does not |
3377 |
require parsing. Instead, an old HTTP convention specified |
3378 |
that what followed was an ASCII (MIME ``text/plain'') body. |
3379 |
Its presence is an optimization. There is no closing tag. |
3380 |
|
3381 |
Example of use: |
3382 |
|
3383 |
<PLAINTEXT> |
3384 |
0001 This is line one of a long listing |
3385 |
0002 file from <ANY@HOST.INC.COM> which is sent |
3386 |
|
3387 |
|
3388 |
11.2.4. Example and Listing Elements |
3389 |
|
3390 |
<XMP> ... </XMP> and <LISTING> ... </LISTING> |
3391 |
|
3392 |
The Example and Listing elements have been replaced by the |
3393 |
Preformatted Text element (Section 10.2). |
3394 |
|
3395 |
These styles allow text of fixed-width characters to be |
3396 |
embedded absolutely as is into the document. The syntax is: |
3397 |
|
3398 |
<LISTING> ... </LISTING> |
3399 |
|
3400 |
or |
3401 |
|
3402 |
<XMP> ... </XMP> |
3403 |
|
3404 |
The text between these tags is typically rendered in a |
3405 |
monospaced font so that any formatting done by character |
3406 |
spacing on successive lines will be maintained. |
3407 |
|
3408 |
Between the opening and closing tags: |
3409 |
|
3410 |
* The text may contain any ISO Latin-1 printable |
3411 |
characters, except for the end-tag opener. The Example |
3412 |
and Listing elements have historically used |
3413 |
specifications which do not conform to SGML. |
3414 |
Specifically, the text may contain ISO Latin printable |
3415 |
characters, including the tag opener, as long it they |
3416 |
does not contain the closing tag in full. |
3417 |
|
3418 |
* SGML does not support this form. HTML interpreters |
3419 |
may vary on how they interpret other tags within |
3420 |
Example and Listing elements. |
3421 |
|
3422 |
* Line boundaries within the text are rendered as a |
3423 |
move to the beginning of the next line, except for one |
3424 |
immediately following a start-tag or immediately |
3425 |
preceding an end-tag. |
3426 |
|
3427 |
* The horizontal tab character must be interpreted as |
3428 |
the smallest positive nonzero number of spaces which |
3429 |
will leave the number of characters so far on the line |
3430 |
as a multiple of 8. Its use is not recommended. |
3431 |
|
3432 |
The Listing element is rendered so that at least 132 |
3433 |
characters fit on a line. The Example element is rendered to |
3434 |
that at least 80 characters fit on a line but is otherwise |
3435 |
identical to the Listing element. |
3436 |
|
3437 |
|
3438 |
11.3. Proposed Features |
3439 |
|
3440 |
This section describes proposed HTML elements and entities |
3441 |
that are not currently supported under HTML Levels 1, or 2, |
3442 |
but may be supported in the future. |
3443 |
|
3444 |
|
3445 |
11.3.1. Additional Character Entities |
3446 |
|
3447 |
To indicate special characters, HTML uses entity or numeric |
3448 |
representations. Additional character presentations are |
3449 |
proposed: |
3450 |
|
3451 |
CHARACTER REPRESENTATION |
3452 |
Non-breaking space |
3453 |
Soft-hyphen ­ |
3454 |
Registered ® |
3455 |
Copyright © |
3456 |
|
3457 |
|
3458 |
11.3.2. Defining Instance Element |
3459 |
|
3460 |
<DFN> ... </DFN> |
3461 |
|
3462 |
The Defining Instance element indicates the defining |
3463 |
instance of a term. The typical rendering is bold or bold |
3464 |
italic. This element is not widely supported. |
3465 |
|
3466 |
|
3467 |
11.3.3. Strike Element |
3468 |
|
3469 |
<STRIKE> ... </STRIKE> |
3470 |
|
3471 |
The Strike element is proposed to indicate strikethrough, a |
3472 |
font style in which a horizontal line appears through |
3473 |
characters. This element is not widely supported. |
3474 |
|
3475 |
|
3476 |
11.3.4. Underline Element |
3477 |
|
3478 |
<U> ... </U> |
3479 |
|
3480 |
The Underline element is proposed to indicate that the text |
3481 |
should be rendered as underlined. This proposed tag is not |
3482 |
supported by all HTML interpreters. |
3483 |
|
3484 |
Example of use: |
3485 |
|
3486 |
The text <U>shown here</U> is rendered in the |
3487 |
document as underlined. |
3488 |
|
3489 |
|
3490 |
12. Acknowledgments |
3491 |
|
3492 |
The HTML document type was designed by Tim Berners-Lee at |
3493 |
CERN as part of the 1990 World Wide Web project. In 1992, |
3494 |
Dan Connolly wrote the HTML Document Type Definition (DTD) |
3495 |
and a brief HTML specification. |
3496 |
|
3497 |
Since 1993, a wide variety of Internet participants have |
3498 |
contributed to the evolution of HTML, which has included the |
3499 |
addition of in-line images introduced by the NCSA Mosaic |
3500 |
software for WWW. Dave Raggett played an important role in |
3501 |
deriving the FORMS material from the HTML+ specification. |
3502 |
|
3503 |
Dan Connolly and Karen Olson Muldrow rewrote the HTML |
3504 |
Specification in 1994. The document was then edited by the |
3505 |
HTML working group as a whole, with updates being made by |
3506 |
Eric Schieler, Mike Knezovich, and Eric W. Sink at Spyglass, |
3507 |
Inc. Finally, Roy Fielding restructured the entire draft |
3508 |
into its current form. |
3509 |
|
3510 |
Special thanks to the many people who have contributed to |
3511 |
this specification: |
3512 |
|
3513 |
Terry Allen Marc Andreessen |
3514 |
|
3515 |
Tim Berners-Lee Paul Burchard |
3516 |
|
3517 |
James Clark Daniel W. Connolly |
3518 |
|
3519 |
Roy T. Fielding Peter Flynn |
3520 |
|
3521 |
Jay Glicksman Paul Grosso |
3522 |
|
3523 |
Eduardo Gutentag Bill Hefley |
3524 |
|
3525 |
Chung-Jen Ho Mike Knezovich |
3526 |
|
3527 |
Tom Magliery Murray Maloney |
3528 |
|
3529 |
Larry Masinter Karen Olson Muldrow |
3530 |
|
3531 |
Bill Perry Dave Raggett |
3532 |
|
3533 |
E. Corprew Reed Yuri Rubinsky |
3534 |
|
3535 |
Eric Schieler James L. Seidman |
3536 |
|
3537 |
Eric W. Sink Stuart Weibel |
3538 |
|
3539 |
Chris Wilson Francois Yergeau |
3540 |
|
3541 |
|
3542 |
12.1. Authors' Addresses |
3543 |
|
3544 |
Tim Berners-Lee |
3545 |
|
3546 |
Director, W3 Consortium |
3547 |
MIT Laboratory for Computer Science |
3548 |
545 Technology Square |
3549 |
Cambridge, MA 02139, U.S.A. |
3550 |
Tel: +1 (617) 253 9670 |
3551 |
Fax: +1 (617) 258 8682 |
3552 |
Email: timbl@w3.org |
3553 |
|
3554 |
Daniel W. |
3555 |
Connolly |
3556 |
|
3557 |
Research Technical Staff, W3 Consortium |
3558 |
MIT Laboratory for Computer Science |
3559 |
545 Technology Square |
3560 |
Cambridge, MA 02139, U.S.A. |
3561 |
Fax: +1 (617) 258 8682 |
3562 |
Email: connolly@w3.org |
3563 |
URI: http://www.w3.org/hypertext/WWW/People/Connolly/ |
3564 |
|