Meta Tag - proposal (suggestions ???)

Davide Musella (davidmsl@anti.tesi.dsi.unimi.it)
Mon, 13 Nov 1995 12:29:33 +0100 (MET)


From: davidmsl@anti.tesi.dsi.unimi.it (Davide Musella)
Message-Id: <9511131129.AA28117@anti.tesi.dsi.unimi.it>
Subject: Meta Tag - proposal (suggestions ???)
To: www-html@w3.org (Mailing list di html)
Date: Mon, 13 Nov 1995 12:29:33 +0100 (MET)

Request for comments, suggestions, etc...
I've only formalized the meta tag definition of the
draft-ietf-html-specv3-00.txt
I need it to create a complete environment for  the research agents.
Suggestions are welcome!!
Davide
davidmsl@anti.tesi.dsi.unimi.it
---------------------------------



INTERNET DRAFT                                     Davide Musella
draft-musella-html-meta-00.txt(???)          National Research Council
                                                   November 1995


                       The META Tag of HTML



Status of this Memo

[...]

Abstract

   This document define a strict synopsis for the META Tag of HTML.
   The grammar will be extended to the contents of the HTTP-EQUIV field,
   defining a set of words to use to allow cataloging of the document.

1.Introduction

   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 rappresent the same concepts with two differents 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 2.0 definition)

   The META element is used within the HEAD element to embed document
   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: 

   NAME 
   CONTENT 
   HTTP-EQUIV 

 2.NAME.

   This attributes could be used to define some property 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.
   This tag is not processed by the HTTP server.

 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 HTPP 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		
	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
	public (yes,no): to indicate if the document is available to averybody
			 or not
	
	
   An HTTP server can process these tags for an HEAD HTTP request, but each
   server can choose which one handle.
   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. 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 rappresent by the SPACE (ASCII[32]) and the OR
   operator with 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 viceversa are ignored.