$0
+ is not allowed for HTML document.The character encoding used for the document is not allowed + for HTML document. The document is non‐conforming.
+$0
+ should not be used for HTML document.The character encoding used for the document is not recommended + for HTML document. The document is non‐conforming + unless there is any good reason to use that encoding.
+Use of UTF-8 as the character encoding of the document is encouraged, + though the use of another character encoding is still conforming.
+The conformance checker cannot detect whether the input document + met the requirements on character encoding, since the document + is not inputed as a serialized byte sequence. The document is + not conforming if it is not encoded in an appropriate character + encoding with appropriate labeling.
+The document does not contain a character encoding + declaration. Unless the character encoding is explicitly + specified in lower‐level protocol, e.g. in HTTP, + or is implied by BOM, there must be a character + encoding declaration. The document is non‐conforming.
+ +The long character encoding declaration syntax
+ <meta http-equiv="Content-Type" content="text/html; charset=charset-name">
+ is obsolete. The new syntax is:
<meta charset="charset-name">Note that the encoding declaration in XML
+ declaration has no effect for HTML document.
$0
+ is not a superset of ASCII.The document is not labeled with character encoding name + in lower‐level protocol, e.g. in HTTP, and + the document is not begin with BOM. In addition, + the character encoding of the document is not a superset of + ASCII. The document is non‐conforming.
+ +Unless there is a BOM, the character encoding + for the document must be specified in e.g. HTTP‐level, + as:
+Content-Type: text/html; charset=charset-nameExistence of HTML character encoding declaration, i.e.
+ <meta charset="charset-name">,
+ does not allow to omit charset parameter
+ for HTML document encoded in non‐ASCII
+ compatible encoding.
Character encodings Shift_JIS, Windows-31J,
+ and ISO-2022-JP are not a superset of
+ ASCII for the purpose of HTML conformance.
$0, a character encoding declaration specifying
+ character encoding as $1 is found. The document
+ is reparsed.While parsing a document in a character encoding, + a character encoding declaration which declares the character + encoding of the document as another character encoding is found. + The occurence of this warning itself does not make the document + non‐conforming. However, the failure of the first attempt to + to detect the character encoding might be a result of non‐conformance + of the document.
+ +The document will be reparsed from the beginning. Some error + or warning might be reported again.
+ +These are suggestions to avoid this warning:
+charset parameter in the Content-Type
+ field in the HTTP header, as:
+ Content-Type: text/html; charset="charset-name"<meta charset="charset-name">)
+ just after <head> start tag.UTF-8.$0 element cannot be
- inserted between head and body elements.<$0>
+ is not allowed after the end tag </html>.A start tag occurs after the head element is closed
- but before the body element is opened.
+
The start or end tag of an element appears after the
+ html element has been closed. The document is
+ non-conforming.
Any content of the document other than comments
+ must be put into the html element.
<$0>
+ is not allowed after the end tag </body>.The start or end tag of an element appears after the
+ body element has been closed. The document is
+ non-conforming.
Any content of the document other than head
+ contents and comments must be put into the body
+ element.
& character must
+ introduce a reference.An & character which
+ is not part of any reference appears in the input stream.
+ The document is non‐conforming.
Any & character in URI (or IRI)
+ must be escaped as &.
The & character must
+ be the first character of a reference:
+
&entity-name;&#d;&#xh;To represent & as a data character, use
+ named entity reference:
+
&</ string is not followed
+ by a tag name.There is a < (U+003C
+ LESS-THAN SIGN) character
+ immediately followed by a / (U+005F
+ SOLIDUS) character, which is not part
+ of any end tag, in the input stream. The document
+ is non-conforming.
The </ sequence immediately followed
+ by an EOF is
+ interpreted as a string data of </.
The </ sequence as string data must
+ be escaped as:
+
</< character is not followed
+ by tag name or by a ! character.A < (U+003C
+ LESS-THAN SIGN) character which is not part
+ of any markup appears in the input stream.
The < character as a data character must
+ be escaped as:
+
<&#.An & (U+0026
+ AMPERSAND) character immediately
+ followed by a # (U+0023
+ NUMBER SIGN) character which
+ is not part of any reference appears in the input stream.
The document is non-conforming.
The string &# must be the first two characters
+ of a reference:
+
&#d;&#xh;To represent &# as data characters, use
+ a named entity reference for the & character:
+
&#&#x.The string &#x or &#X which
+ is not part of any reference appears in the input stream.
+ The document is non-conforming.
The string &#x or &#X must
+ be the first three characters of a hexadecimal reference:
+
&#xh;To represent &#x as data characters, use
+ a named entity reference for the & character:
+
&#x<! is not followed
+ by --.There is a < (U+003C
+ LESS-THAN SIGN) character
+ followed by a ! (U+0021
+ EXCLAMATION MARK) character,
+ which is not followed by a -- or
+ !DOCTYPE. The document is non-conforming.
<!-- (<!
+ immediately followed
+ by two -s) and must be terminated by
+ -->.
+ Strings <! not followed
+ by -- and <!- not followed by
+ - are not valid open delimiters for comments.CDATA sectionsDOCTYPE
+ and comment declarations, are not allowed in HTML document.<!<! must be escaped as
+ <!.</ is not followed
+ by tag name.There is a < (U+003C
+ LESS-THAN SIGN) character
+ immediately followed by a / (U+005F
+ SOLIDUS) character, which is not part
+ of any end tag, in the input stream. The document
+ is non-conforming.
The </ sequence not followed by a
+ tag name is parsed as an opening of bogus comment.
The </ sequence as string data must
+ be escaped as:
+
</-- sequence
+ in a comment.There is a - (U+002D
+ HYPHEN-MINUS) character
+ at the end of the comment or a -- sequence
+ in the comment. The document is non-conforming.
Comments cannot contain a string --, as in XML.
+ Unlike SGML, there cannot be more than one comments
+ (where comment is an SGML term) in the comment
+ declaration.
$0.Attributes must be unique in an element. Specifying - attributes with same name more than once is non-conforming.
+There are more than one attributes with the same + name in a tag. The document is non-conforming.
The motion attribute is not part of the HTML standard.
Use img element with animation GIF instead.
/>) cannot be
+ />) cannot be
used for this element.The void element syntax /> syntax can only be
+
Polytheistic slash (/>) must not be used
+ for the element. The document is non-conforming.
The polytheistic slash can only be
used for base, link, meta,
hr, br, img,
embed, param, area,
- col, and input elements.
- For any other elements, using that syntax is non-conforming.
col, and input elements.
+
+ <script/>The polytheistic slash cannot be used for script
+ element. Even for an empty script element,
+ there must be an explicit end tag
+ </script>.
NOTE: Though some user agents interpret
+ polytheistic slash for script element as the
+ closing of the element, such usage is not allowed under
+ the current standard.
<basefont/>, <bgsound/>,
+ <frame/>, <keygen/>,
+ <spacer/>, <wbr/><command/>, <event-source/>,
+ <nest/>, or <source/><a/>, <p/><p></p>Unlike XML, the void element syntax (/>) has
+
Note that, unlike in XML, the polytheistic slash has no effect in HTML.
<?...>) cannot be used.Processing instructions (<?...?>),
+ including XML declaration (<?xml ...?>)
+ and XML style sheet PI
+ (<?xml-stylesheet ...?>), are not allowed
+ in the HTML syntax. The document is non-conforming.
<?xbl?> (XBL Association)binding property in CSS
+ style sheet as:
+ <style>
+p {
+ binding: url(binding.xbl);
+}
+</style><?xml?> (XML declaration)<?xml-stylesheet?> (XML style sheet
+ PI)link element with rel
+ attribute set to stylesheet (or,
+ alternate stylesheet for an alternate style
+ sheet).
+ <link rel=stylesheet href="path/to/stylesheet.css"><?php?> or
+ <? ... PHP code ... ?>
+ (PHP code)ProcessingInstruction node by scripting.Web browsers will parse processing instructions as bogus + comments. Some legacy Web browsers, such as IE:mac and + some mobile Web browsers, will display processing instructions + as string.
+$0 element cannot be
+ inserted between head and body elements.A start tag appears after the head element is closed
+ but before the body element is opened.
+ The document is non-conforming.
DOCTYPE appears after any
+ element or data character has been seen.A DOCTYPE appears after any element or data character
+ has been seen. The document is non-conforming.
The DOCTYPE must be placed before any
+ tag, reference, or data character. Only white space characters
+ and comments can be inserted before the DOCTYPE.
HTML a elements cannot be nested.
+ The document is non-conforming.
In the HTML syntax, a start tag of the a
+ implies the end tag of any opening a element.
<$0>
+ is not allowed in the body element.The start or end tag of an element, which
+ cannot be a descendant of body element, appears
+ in the input stream while the body element has been opened.
+ The document is non-conforming.
<head>
+ is not allowed in the head element.There is a start tag <head> in the
+ <head> element. The document is non-conforming.
In an HTML document there must not be more than
+ one head element, therefore no more than one
+ start tag <head> can appear in the input stream.
<$0>
+ is not allowed in a table element.The start or end tag of an element, which
+ cannot be a child of table element, appears
+ in the input stream while the table element has been opened
+ but no other element has been opened. The document is non-conforming.
In table, only table related elements
+ are allowed; any other element must be contained in
+ td or th element to form
+ a part of the table, or caption element to create
+ a table caption.
table.A data character appears in table. The document
+ is non-conforming.
In table, only table related elements
+ are allowed; any other element and data character must be contained in
+ td or th element to form
+ a part of the table, or caption element to create
+ a table caption.
tr
+ element is missing.Start tag of a tr element, which is not
+ optional, is missing. The document is non-conforming.
In a table section, a <tr> start tag
+ must occur before any <td> or
+ <th> start tag. Though the HTML5 parser
+ implies the <tr> start tag before
+ these start tags, it must be explicitly specified.
DOCTYPE.The document does not start with a DOCTYPE.
+ The document is non-conforming.
An HTML document must start by a DOCTYPE:
+
<!DOCTYPE HTML>Only white space characters and comments are allowed
+ before the DOCTYPE. XML declaration is not
+ allowed in HTML document.
$0 is not
+ closed.End tag of an element is not found before, for example, + an end tag of another element appears or + the end of the document. The document is non-conforming.
+ +Only body, colgroup, dd,
+ dt, head, html, li,
+ ol, option, optgroup,
+ p, rb, rp, rt,
+ tbody, td, tfoot,
+ th, thead, tr,
+ ul end tag can be omitted in HTML documents.
+ For any element except for void element, there must be an explicit
+ end tag.
canvas elementcanvas element is no longer
+ defined as empty. There must be an end tag
+ </canvas>.Note that misnesting tags, such as
+ <a><b></a></b>, are not
+ allowed and they also cause this error.
<html> tag is not
+ the first start tag.There is a start tag of the html element
+ that it not the first start tag in the input stream.
+ The document is non-conforming.
In an HTML document, there cannot be more than one
+ html element and therefore there cannot be
+ more than one <html> tag. In addition,
+ nothing can be placed before the <html> tag
+ except a DOCTYPE, white space characters,
+ and comments.
The document contains a DOCTYPE declaration
+ that is different from HTML5 DOCTYPE (i.e.
+ <!DOCTYPE HTML>).
+ The document is non‐conforming.
The document might or might not be conformant to + some version of HTML. However, conformance to any HTML + specification other than HTML5 provides for no practical + convenience, since Web borwsers will parse any + HTML document (roughly) as defined in HTML5.
+$0 is not
+ opened.An end tag appears though no element with the same name + has been opened. The document is non-conforming.
+ +For any end tag in HTML document, there must be a + corresponding start tag.
+ +base, basefont,
+ bgsound, br, col,
+ embed, frame, hr,
+ image, img, input,
+ isindex, link, meta,
+ param, spacer, or wbr elementA data character occurs where it is not allowed in this +
A data character appears where it is not allowed in this context. The document is non-conforming.
Possible causes: -
a or span)A data character cannot be a child
- of certain sectioning elements such as body,
- section, and blockquote.
Any inline-level content must be put
- in e.g. paragraph element such as p.
div or hn)Though some elements such as div,
- li, and td allow
- either one of block-level or inline-level content
- is allowed. If there is a block-level content,
- any inline-level content must be put
- in e.g. paragraph element such as p.
A data character cannot be a child
+ of certain sectioning elements such as body,
+ section, and blockquote.
Any inline-level content must be put
+ in e.g. paragraph element such as p.
Though some elements such as div,
+ li, and td allow
+ either one of block-level or inline-level content
+ is allowed. If there is a block-level content,
+ any inline-level content must be put
+ in e.g. paragraph element such as p.
The content model of the element is so defined that it
must contain a $0 child element.
- Without such an element, the document is non-conforming.
For example: -
head element must contain exactly one
- title child element.tr
- element must contain one or more td or th
- child element.head elementtitle child element.html elementhead child element followed
+ by a body element.tr elementtd or th child element.th element as a child of this element.
The tr element must contain at least one
- td or th child element. Without
- such an element, the document is non-conforming.
td or th child element. The document
+ is non-conforming.
An element occurs where it is not allowed. The document +
An element appears where it is not allowed. The document is non-conforming.
Possible causes: -
a or span)a, progress, or imgAn inline-level element cannot be a child
of certain sectioning elements such as body,
section, and blockquote.
Any inline-level content must be put
in e.g. paragraph element such as p.
div or hn)Though some elements such as div,
- li, and td allow
- either one of block-level or inline-level content
- is allowed. If there is a block-level content,
- any inline-level content must be put
- in e.g. paragraph element such as p.
html elementIn an XHTML document, the root html
- element must have an xmlns attribute
- whose value is set to
- http://www.w3.org/1999/xhtml.
aside,
+ div, hn,
+ p, or sectiondiv,
+ li, td, or thThe parent element allows either
+ block-level or inline-level content. If there is a
+ block-level content, any inline-level content must be
+ put in e.g. paragraph element such as p.
For example, an HTML document fragment
+ <div><p>Hello!</p> World!</div>
+ is non-conforming, since a word World!
does not belong
+ to any paragraph. (If not part of any paragraph, what is
+ it!?) A conforming example would be:
+
<div><p>Hello!</p> <p>World!</p></div>div element cannot be
+ a child of an h1 element.noscript elementnoscript element is allowed only in the context
+ where a block-level or inline-level content is expected
+ and in the head element.
+ It cannot be used in e.g. ul, table,
+ or select.blink,
+ center, or marquee elementbutton, datalist,
+ fieldset, form,
+ input, label,
+ optgroup, option, output,
+ rb, rp, rt, ruby,
+ textarea, or textarea elementDOCTYPE declaration.
-not HTML5;parse-error;This document is written in an old version of HTML.
-not closed;parse-error;Element $0 is not closed.
-unmatched end tag;parse-error;Element $0 is not opened.
-
-table:no cell in last row;table-model-error;The table has no cell (td or th) in the last row.
-
-s:IMT:obsolete subtype;should;An obsolete subtype is used.
-s:IMT:private subtype;should;A private (x- or x.) subtype is used.
-s:IMT:unregistered subtype;should;The subtype is not registered to IANA.
+An element that is not allowed as the root element + is used as the root element of the document. The document is + non-conforming, as far as the conformance checker can tell.
+ +html element in an XHTML documentIn XHTML document, the root html
+ element must have an xmlns attribute as:
+
<html xmlns="http://www.w3.org/1999/xhtml">rss elementThe document is written in some version of RSS.
+The conformance checker does not support any version + of RSS. Use Atom 1.0 for feed documents.
feed elementThe Atom feed element must be
+ in the http://www.w3.org/2005/Atom
+ namespace as:
+
<feed xmlns="http://www.w3.org/2005/Atom">The conformance checker does not support Atom 0.3. + Use Atom 1.0 for feed documents.
$0
+ element before this element.There must be an element before another element, but there + is not. The document is non-conforming.
+ +For example, there must be a dt element
+ before any dd element.
$0
+ is not specified.A required attribute is not specified. The document + is non-conforming.
+ +Some attribute is defined as required. + Without required attributes specified, user agents + cannot provide full functionality of the element to the user.
+ +img elementsrc attribute must be specified.
+ Additionally, the alt attribute must be specified
+ in many cases.link elementrel attribute must be specified.
+ Note that the rev attribute is obsolete.{local-name} is not allowed for
+ {element-local-name} element.An attribute is specified where it is not allowed. + The document is non-conforming.
+ +meta elementmeta element, only one of
+ name, http-equiv, or charset
+ attribute is allowed.xml:lang attribute is not
+ allowed in HTML document.The xml:lang attribute is not allowed in
+ HTML document. The document is non-conforming.
Use of the xml:lang attribute is conforming
+ only in XML documents.
To specify natural language information in HTML document,
+ use lang attribute instead.
XHTML 1.0 Appendix C was encouraged to specify both
+ lang and xml:lang attributes with
+ the same value. Such a duplication has no effect in practice.
+ Use only one of lang (in HTML) or xml:lang (in
+ XML).
charset attribute is not
+ allowed in XML document.The charset attribute of a
+ meta element is not allowed in XML document.
+ The document is non-conforming.
To specify the character encoding used for serialization, + if necessary, use XML declaration instead: +
<?xml version="1.0" encoding="encoding-name"?>lang attribute is not
+ allowed in XML document.The HTML lang attribute is not allowed in
+ XML document. The document is non-conforming.
The lang attribute in null
+ namespace for HTML elements is conforming only in
+ HTML documents.
To specify natural language information in XML document,
+ use xml:lang attribute instead.
xmlns attribute
+ in the null namespace is not allowed in
+ XHTML document. The document is non-conforming.The xmlns attribute in the null
+ namespace is not allowed in XHTML document.
This error should not occur in conformance-checking of + static documents.
+$0
+ is not registered.The specified character encoding name is not registered to + IANA. Use of registered character encoding name + is a good practice to facilitate interoperability.
+ +EUC-TWEUC-TW is not registered. Unfortunately, there
+ is no registered name for that character encoding. Use
+ Big5 encoding with character encoding name Big5
+ if it is enough to represent the document.ISO-2022-JP-1ISO-2022-JP-1 is not registered, nevertheless
+ this character encoding name is documented in
+ RFC 2237. Use
+ ISO-2022-JP-2 instead, since that character encoding
+ is a superset of ISO-2022-JP-1.ISO-2022-JP-3, ISO-2022-JP-3-plane1ISO-2022-JP-2004 and
+ ISO-2022-JP-2004-plane1.ISO-2022-JP-2003,
+ ISO-2022-JP-2003-plane1ISO-2022-JP-2004 and
+ ISO-2022-JP-2004-plane1.ISO-2022-JP-2004,
+ ISO-2022-JP-2004-plane1UTF-8NUTF-8N is not registered. Character encoding
+ name UTF-8 represents UTF-8 encoding with or
+ without BOM.WARNING: This error might be raised for + a registered character encoding name, since the character encoding + name database of the conformance checker is not complete yet.
+$0 is a private
+ character encoding name.The specified character encoding name is a private name and + not registered to IANA. Use of registered character + encoding name is a good practice to facilitate interoperability.
+ +x-euc-jpEUC-JP for the Japanese EUC
+ character encoding.x-sjisShift_JIS for standard Shift encoding scheme of
+ JIS coded character set, or Windows-31J
+ for Microsoft standard character set as implemented by
+ Microsoft Windows.The attribute value must be a character encoding name. However, + the specified value is not a character encoding name syntactically. + The document is non‐conforming.
+Character encoding name is a string of ASCII + printable characters, up to 40 characters.
+{@} is not one
+ of them.For this attribute only several values are allowed and the + value of the attribute is not one of them. The document + is non-conforming.
+ +meta element, http-equiv attributeOnly values Default-Style and Refresh
+ are allowed.
Value Content-Type is obsolete; for charset
+ declaration, the charset attribute can be used as:
+
<meta charset="charset-name">utf-8.
+ Values Content-Style-Type and
+ Content-Script-Type are currently not allowed.
Value Keywords is not allowed. Use
+ name attribute instead of http-equiv
+ attribute.
Values Expires, Pragma,
+ and Cache-Control are not allowed;
+ use real HTTP header fields for cache control.
<meta http-equiv="Content-Type" content="text/html; charset=charset-name">
+ is obsolete.Old long character encoding declaration syntax
+ <meta http-equiv="Content-Type" content="text/html; charset=charset-name">
+ is in use. The document is non‐conforming.
The new character encoding declaration syntax is: +
<meta charset="charset-name">$0
+ cannot be specified for this element.The specified link type cannot be used for the element. + The document is non-conforming.
+ +Link types are associated with limited set of elements. + They cannot be used with other elements.
+ +For example, link type bookmark
+ can be used with a or area element,
+ while it cannot be used with link element.
$0
+ is non-conforming.The specified link type is non-conforming, and therefore + the document is non-conforming.
+ +contentsindex.copyrightlicense.homeindex.previousprev.startfirst.toc or topindex.$1
+ is different from document character encoding
+ $0.The specified character encoding name is different from + the character encoding of the document. The document + is non‐conforming.
+{@} is reserved.The specified browsing context name is reserved. + The document is non-conforming.
+ +Names of browsing contexts starting with _
+ (U+005F LOW LINE)
+ are reserved so that it must not be used.
Old version of HTML, non-HTML markup languages, and
+ Web browsers define or implements special reserved
+ browsing context names _blank,
+ _main, and _replace.
+ However, they are not conforming attribute values.
$0
+ is proposed but not accepted yet; it should not be
+ used until it has been accepted.The link type is in the proposed status; it + should not be used until it has been + accepted.
+ +Warning: The data served to the + conforming checker might be out of date; it might have already + been accepted or rejected. The document might or might not be + conforming depending on the status. See WHATWG Wiki + for the latest information.
+colspan attribute
+ results in creating a table column that does not contain
+ any cell anchored to it.td or
+ th) in the last row.rowspan attribute
+ results in creating a table row that does not contain
+ any cell anchored to it.The rowspan attribute value of the cell
+ is so specified that it extends a table in the row axis.
+ However, the extended row does not contain any cell by itself.
+ The document is non-conforming.
For example, the table below is non-conforming: +
<table>
+<tbody>
+<tr><td rowspan=2></td></tr>
+</tbody>
+</table>{@}: An obsolete
+ subtype is used.The specified Internet Media Type is registered with status + of OBSOLETE.
+ +text/ecmascripttext/ecmascript is obsoleted in
+ favor of application/ecmascript. Note that
+ text/javascript would be better alternative
+ for many cases.text/javascripttext/javascript is obsoleted by
+ IETF with backward incompatible alternate
+ application/javascript for architectural
+ purity. Realist may ignore this warning.{@}: A private
+ (x- or x.) subtype is used.{@}: The subtype is
+ not registered to IANA.The specified value does not satisfy the syntactical requirements + for IRI references. The document is non-conforming.
+ +Possible causes: +
(U+0020
+ SPACE) character cannot be
+ used in IRI references.. or
+ ..) occurs in an absolute reference.Dot-segment (. or ..) should
+ not occur in an absolute reference.
In relative references, dot-segments are used to represent
+ the current (.) or the parent (..)
+ hierarchy of the path. Though they are also allowed
+ in absolute references, it should be resolved to the
+ canonical form before it has been published.
/.The IRI does not end with a /. If there is an
+ authority component in an IRI, a / should be present
+ instead of empty path component.
For example, http://www.example.com/
+ is preferred to http://www.example.com.
The hexadecimal digit in percent-encoding string in the IRI + is in lowercase. Though the IRI is conforming, + it should be in uppercase.
+An unreserved character is percent-encoded in the IRI. + Though it is conforming, it should be in the + decoded (or bare) form.
+The scheme part of the IRI is written in uppercase letter.
-s:URI::empty path;should;This IRI should explicitly end with/.
-m:URI::syntax error;must;This IRI is not syntactically valid.
+ Uppercase scheme names are not required to be processed + correctly.
+ +The specified document is not a cache manifest. + The document is non-conforming.
+ +An entity labeled as Internet media type
+ text/cache-manifest must contain a cache manifest.
A cache manifest must start with a line whose content is
+ CACHE MANIFEST
+ (exactly one space character between
+ CACHE and MANIFEST).
The element is in the call for implementation stage.
+ +Usually, using the element is safe. However, it is a new feature + so that it might not be implemented correctly. If it is found that + the feature is hard or impossible to implement, the feature + might be revised, or in some case it might be dropped.
+ +Elements defined by Atom 1.0 (IETF Proposed Standard), and XBL 2.0 + (W3C Candidate Recommendation) belong to this class.
+The element is in the last call for comments stage.
+ +The element is relatively mature, though the standardization + is not done yet. It may be used for experiments. Since it is a new + feature, it might not be implemented correctly or at all. If it is + found that the feature is hard or impossible to implement, the feature + might be revised or might be dropped.
+ +Elements defined by Web Forms 2.0 as well as some elements + defined by HTML5 belong to this class.
+The element is documented in a working or editor's draft + and not yet completed.
+ +The element should not be used for any practical purpose. + The feature might be drastically changed later or might be + entirely removed.
+ +Most of new elements defined by HTML5 belong to this class.
+The element is not part of any standard or draft the conformance + checker is aware of.
+ +The element should not be used for any practical purpose unless + there is really a standard that defines the element.
+{local-name} is not supported; it might or
+ might not be conforming.The conformant checker does not support the attribute. +
The conformant checker does not support the element. It cannot determine whether the document is conforming or not.
{local-name} of element
+ {element-local-name} is not supported;
+ it might or might not be conforming.The conformant checker does not support the element. +
The conformant checker does not support the attribute. It cannot determine whether the document is conforming or not.
$0 is not standardized
- or registered at the time of the release of the conformance checker;
- it is non-conforming unless it has now been registered.$0 is not
+ standardized or registered at the time of the release of the conformance
+ checker; it is non-conforming unless it now has been
+ registered.The rel attribute is defined as a list of link types.
Some common link types are defined in the HTML5 specification.
@@ -214,19 +1560,114 @@
The link type might have been added to the registry since then.
In such case it might be conforming. Otherwise, the
document is non-conforming.
shortcut iconshortcut is not registered.
+ Use only icon for linking to so-called favicon.$0 is not supported;
+ it might or might not be conforming.$0 is not supported;
+ it might or might not be conforming.| Level | +Conforming? | +Description | +
|---|---|---|
| MUST‐level error | +Non‐conforming. | +A violation to a hard requirement of the specification. +The document is non‐conforming. | +
| SHOULD‐level error | +Non‐conforming, but in some case +conforming. | +A violation to a requirement of the specification. +The violation might be legitimize in some case. Otherwise, +the document is non‐conforming. | +
| Warning | +Conforming. | +A warning is an advice from the conformance checker to avoid +to solve a problem in a confusing or possibly wrong way. +It does not affect to the conformance of the document, and +may sometimes be inappropriate. | +
| Information | +Conforming. | +An informational message just provides an additional information +on the feature used in the document or the status of the retrieval +or so on. +It does not affect to the conformance of the document. | +
| Not supported | +Unknown. | +Some feature that is not supported by the conformance checker +is used in the document. | +
Copyright 2007 Wakaba
-This library is free software; you can redistribute it +
Copyright ‐
+Wakaba
+<w@suika.fam.cx>.
This document is free software; you can redistribute it and/or modify it under the same terms as Perl itself.