2004/id/draft-musella-html-metatag-01.txt



INTERNET DRAFT                                     Davide Musella
draft-musella-html-metatag-01.txt             National Research Council
                                                  20 December 1995 

                       The META Tag of HTML
  
  
  
Status of this Memo  
  
   This document is an Internet-Draft.  Internet-Drafts are working  
   documents of the Internet Engineering Task Force (IETF), its areas,  
   and its working groups.  Note that other groups may also distribute  
   working documents as Internet-Drafts.  
  
   Internet-Drafts are draft documents valid for a maximum of six months  
   and may be updated, replaced, or obsoleted by other documents at any  
   time.  It is inappropriate to use Internet- Drafts as reference  
   material or to cite them other than as ``work in progress.''  
  
   To learn the current status of any Internet-Draft, please check the  
   "1id-abstracts.txt" listing contained in the Internet-Drafts shadow  
   Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),  
   munnari.oz.au (Pacific Rim), ds.internic.net (US East Cost) or  
   ftp.isi.edu (US West Coast).  
  
   Distribution of this document is unlimited. Please send comments to   
   Davide Musella, davidmsl@anti.tesi.dsi.unimi.it or to   
   musella@dsi.unimi.it , (voice) +39.(0)2.70643271  
  
  
Abstract  
  
   This document defines a strict synopsis for the META Tag of HTML.  
   The grammar is extended to the contents of the HTTP-EQUIV field,  
   defining a set of words to use to allow document cataloging.  
  
1. Introduction  
  
   Now the synopsis of the META HTTP-EQUIV Tag is not severe, allowing so   
   the use of different key words to define the same things.  
   The functions like this:  
        <META HTTP-EQUIV = "Keywords" CONTENT = "Italy, Tourism">  
   or  
        <META HTTP-EQUIV = "Keys" CONTENT = "Italy, Tourism">  
   could reppresent the same concepts with two different syntax.  
   The aim of this Draft is to define which are the words to use to   
   define the contents of an HTML document.  
   There are, also, some easy rules to implement a binary logic (AND or  
   OR) for the CONTENT field.  
  
 2. The META Tag (HTML 3.0 definition)  
  
   The META element is used within the HEAD element to embed documents  
   meta-information not defined by other HTML elements. Such information  
   can be extracted by servers/clients for use in identifying, indexing  
   and cataloging specialized document meta-information.  
  
   Although it is generally preferable to used named elements that have  
   well defined semantics for each type of meta-information, such as   
   title, this element is provided for situations where strict SGML   
   parsing is necessary and the local DTD is not extensible.   
  
  
  
  
                         
   In addition, HTTP servers can read the contents of the document head  
   to generate response headers corresponding to any elements defining   
   a value for the attribute HTTP-EQUIV.  This provides document authors  
   with a mechanism (not necessarily the preferred one) for identifying  
   information that should be included in the response headers of an   
   HTTP request.   
  
   The META element has three attributes:   
  
   HTTP-EQUIV  
   NAME   
   CONTENT  
  
 3. HTTP-EQUIV.  
  
   This attribute binds the element to an HTTP response header. If the   
   semantics of the HTTP response header named by this attribute is   
   known, then the contents can be processed based on a well defined   
   syntactic mapping, whether or not the DTD includes anything about it.  
   HTTP header names are not case sensitive. If absent, the NAME   
   attribute should be used to identify this meta-information and it   
   should not be used within an HTTP response header.  
   It is possible to use any text string, but if you want to define   
   these properties you have to use the following words:  
  
        keywords: to indicate the keywords of the document  
        author:   to indicate the author of the document  
        timestamp: to indicate when the document is authored  
        expire:   to indicate the expire date of the document  
        language: to indicate the language of the document  
        abstract: to indicate the abstract of the document  
        organization: to indicate the organization of the author  
        revision: to indicate the revision number of the document  
        public (Boolean): to indicate if the document is available to  
                         everybody or not  
  
  
   An HTTP server must process these tags for an HEAD HTTP request,   
   Do not name an HTTP-EQUIV attribute the same as a response header   
   that should typically only be generated by the HTTP server. Some   
   inappropriate names are "Server", "Date", and "Last-Modified".  
   Whether a name is inappropriate depends on the particular server   
   implementation. It is recommended that servers ignore any META   
   elements that specify HTTP equivalents (case insensitively) to their   
   own reserved response headers.     
                        
 4. NAME.  
  
   This attributes can be used to define some properties such as  
   author, publication date etc. If absent the name can be assumed to be  
   the same as the value of HTTP-EQUIV.  
   An example:  
  
            <META NAME= "Editor" CONTENT = "McDraw Bill">  
  
   Do not use the META element to define information that should be  
   associated with an existing HTML element.  
  
  
 5. CONTENT  
  
   Used to supply a value for a named property.  
   If it's used with the HTTP-EQUIV it can contain more than one single   
   information; it is possible to use the Boolean operator (AND, OR) to   
   insert a Boolean definition of the field.  
   The AND operator will be represented by the SPACE (ASCII[32]) and the   
   OR operator by the COMMA (ASCII[44]).  
   The AND operator is processed before the OR operator. So a string   
   like this: "Red ball, White ball" means :"ball AND (red OR white)".  
   Examples:  
  
   <META HTTP-EQUIV= "Keywords" CONTENT= "Italy Product, Italy Tourism">  
  
   The spaces between a comma and a word or vice versa are ignored.  
     
 6. Cataloging an HTML document

   These 'keywords' were specifically conceived for exaustively and 
   completely catalogue the HTML document.
   This allows the software agents to index at best your own document.
   To do a preliminary indexing, it's important to use at least the 
   http-equiv meta-tag "keywords".
     
    

1
2
3	INTERNET DRAFT Davide Musella
4	draft-musella-html-metatag-01.txt National Research Council
5	20 December 1995
6
7	The META Tag of HTML
8
9
10
11	Status of this Memo
12
13	This document is an Internet-Draft. Internet-Drafts are working
14	documents of the Internet Engineering Task Force (IETF), its areas,
15	and its working groups. Note that other groups may also distribute
16	working documents as Internet-Drafts.
17
18	Internet-Drafts are draft documents valid for a maximum of six months
19	and may be updated, replaced, or obsoleted by other documents at any
20	time. It is inappropriate to use Internet- Drafts as reference
21	material or to cite them other than as ``work in progress.''
22
23	To learn the current status of any Internet-Draft, please check the
24	"1id-abstracts.txt" listing contained in the Internet-Drafts shadow
25	Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
26	munnari.oz.au (Pacific Rim), ds.internic.net (US East Cost) or
27	ftp.isi.edu (US West Coast).
28
29	Distribution of this document is unlimited. Please send comments to
30	Davide Musella, davidmsl@anti.tesi.dsi.unimi.it or to
31	musella@dsi.unimi.it , (voice) +39.(0)2.70643271
32
33
34	Abstract
35
36	This document defines a strict synopsis for the META Tag of HTML.
37	The grammar is extended to the contents of the HTTP-EQUIV field,
38	defining a set of words to use to allow document cataloging.
39
40	1. Introduction
41
42	Now the synopsis of the META HTTP-EQUIV Tag is not severe, allowing so
43	the use of different key words to define the same things.
44	The functions like this:
45	<META HTTP-EQUIV = "Keywords" CONTENT = "Italy, Tourism">
46	or
47	<META HTTP-EQUIV = "Keys" CONTENT = "Italy, Tourism">
48	could reppresent the same concepts with two different syntax.
49	The aim of this Draft is to define which are the words to use to
50	define the contents of an HTML document.
51	There are, also, some easy rules to implement a binary logic (AND or
52	OR) for the CONTENT field.
53
54	2. The META Tag (HTML 3.0 definition)
55
56	The META element is used within the HEAD element to embed documents
57	meta-information not defined by other HTML elements. Such information
58	can be extracted by servers/clients for use in identifying, indexing
59	and cataloging specialized document meta-information.
60
61	Although it is generally preferable to used named elements that have
62	well defined semantics for each type of meta-information, such as
63	title, this element is provided for situations where strict SGML
64	parsing is necessary and the local DTD is not extensible.
65
66
67
68
69
70	In addition, HTTP servers can read the contents of the document head
71	to generate response headers corresponding to any elements defining
72	a value for the attribute HTTP-EQUIV. This provides document authors
73	with a mechanism (not necessarily the preferred one) for identifying
74	information that should be included in the response headers of an
75	HTTP request.
76
77	The META element has three attributes:
78
79	HTTP-EQUIV
80	NAME
81	CONTENT
82
83	3. HTTP-EQUIV.
84
85	This attribute binds the element to an HTTP response header. If the
86	semantics of the HTTP response header named by this attribute is
87	known, then the contents can be processed based on a well defined
88	syntactic mapping, whether or not the DTD includes anything about it.
89	HTTP header names are not case sensitive. If absent, the NAME
90	attribute should be used to identify this meta-information and it
91	should not be used within an HTTP response header.
92	It is possible to use any text string, but if you want to define
93	these properties you have to use the following words:
94
95	keywords: to indicate the keywords of the document
96	author: to indicate the author of the document
97	timestamp: to indicate when the document is authored
98	expire: to indicate the expire date of the document
99	language: to indicate the language of the document
100	abstract: to indicate the abstract of the document
101	organization: to indicate the organization of the author
102	revision: to indicate the revision number of the document
103	public (Boolean): to indicate if the document is available to
104	everybody or not
105
106
107	An HTTP server must process these tags for an HEAD HTTP request,
108	Do not name an HTTP-EQUIV attribute the same as a response header
109	that should typically only be generated by the HTTP server. Some
110	inappropriate names are "Server", "Date", and "Last-Modified".
111	Whether a name is inappropriate depends on the particular server
112	implementation. It is recommended that servers ignore any META
113	elements that specify HTTP equivalents (case insensitively) to their
114	own reserved response headers.
115
116	4. NAME.
117
118	This attributes can be used to define some properties such as
119	author, publication date etc. If absent the name can be assumed to be
120	the same as the value of HTTP-EQUIV.
121	An example:
122
123	<META NAME= "Editor" CONTENT = "McDraw Bill">
124
125	Do not use the META element to define information that should be
126	associated with an existing HTML element.
127
128
129	5. CONTENT
130
131	Used to supply a value for a named property.
132	If it's used with the HTTP-EQUIV it can contain more than one single
133	information; it is possible to use the Boolean operator (AND, OR) to
134	insert a Boolean definition of the field.
135	The AND operator will be represented by the SPACE (ASCII[32]) and the
136	OR operator by the COMMA (ASCII[44]).
137	The AND operator is processed before the OR operator. So a string
138	like this: "Red ball, White ball" means :"ball AND (red OR white)".
139	Examples:
140
141	<META HTTP-EQUIV= "Keywords" CONTENT= "Italy Product, Italy Tourism">
142
143	The spaces between a comma and a word or vice versa are ignored.
144
145	6. Cataloging an HTML document
146
147	These 'keywords' were specifically conceived for exaustively and
148	completely catalogue the HTML document.
149	This allows the software agents to index at best your own document.
150	To do a preliminary indexing, it's important to use at least the
151	http-equiv meta-tag "keywords".
152
153
154