Re: META

Terry Allen (terry@ora.com)
Tue, 27 Jun 95 16:40:51 EDT

>We encourage discussion of how best to accomodate this goal.

In response to Eric's suggestion, one place to begin is the language
in 04.txt. A few comments are appended.

As some of us have discussed, a good solution from the SGML standpoint
would be to add a SCHEME attribute and allow content in META, so that
instead of

<meta name="subject" content="computer networking software">

one could have

<meta scheme="LCSS" name="subject">computer networking software</meta>

this would probably require some change to existing browsers, so that
they don't display "computer networking software", but it should not
be a hard change to make.

So Eric, I'll propose as a straw that we do exactly that:

<!ELEMENT META - O EMPTY>
<!ATTLIST META
HTTP-EQUIV NAME #IMPLIED
NAME NAME #IMPLIED
CONTENT CDATA #REQUIRED >

would become

<!ELEMENT META - - (%text;)*>
<!ATTLIST META
HTTP-EQUIV NAME #IMPLIED
NAME NAME #IMPLIED
SCHEME NAME #IMPLIED >

| 5.2.5. Associated Meta-information: META
|
| The <META> element is an extensible container for use in
| identifying specialized document meta-information.
| Meta-information has two main functions:
|
| * to provide a means to discover that the data set exists
| and how it might be obtained or accessed; and

what data set is intended here?

| * to document the content, quality, and features of a data
| set, indicating its fitness for use.
|
| Each <META> element specifies a name/value pair. If multiple
| META elements are provided with the same name, their combined
| contents--concatenated as a comma-separated list--is the value
| associated with that name.

is that intended to get around length limitations on att values (okay
if so, just asking)?

| NOTE - The <META> element should not be used where a
| specific element, such as <TITLE>, would be more
| appropriate.

so what about proposals for metadata sets that include TITLE as an
element? Should the above note be dropped? modified? should a
metadata UA assume that the TITLE element supplies META NAME=TITLE?
(end of my comments; the rest appears only for convenience)

| HTTP servers may read the content of the document <HEAD> to
| generate header fields corresponding to any elements defining a
| value for the attribute HTTP-EQUIV.
|
| NOTE - The method by which the server extracts document
| meta-information is unspecified and not mandatory. The
| <META> element only provides an extensible mechanism for
| identifying and embedding document meta-information --
| how it may be used is up to the individual server
| implementation and the HTML user agent.
|
| Attributes of the META element:
|
| HTTP-EQUIV
| binds the element to an HTTP header field. An HTTP
| server may use this information to process the document.
| In particular, it may include a header field in the
| responses to requests for this document: the header name
| is taken from the HTTP-EQUIV attribute value, and the
| header value is taken from the value of the CONTENT
| attribute. HTTP header names are not case sensitive.
|
| NAME
| specifies the name of the name/value pair. If not
| present, HTTP-EQUIV gives the name.
|
| CONTENT
| specifies the value of the name/value pair.
|
| Examples
|
| If the document contains:
|
| <META HTTP-EQUIV="Expires"
| CONTENT="Tue, 04 Dec 1993 21:29:02 GMT">
| <meta http-equiv="Keywords" CONTENT="Fred">
| <META HTTP-EQUIV="Reply-to"
| content="fielding@ics.uci.edu (Roy Fielding)">
| <Meta Http-equiv="Keywords" CONTENT="Barney">
|
| then the server may include the following header fields:
|
| Expires: Tue, 04 Dec 1993 21:29:02 GMT
| Keywords: Fred, Barney
| Reply-to: fielding@ics.uci.edu (Roy Fielding)
|
| as part of the HTTP response to a `GET' or `HEAD' request for
| that document.
|
| An HTTP server must not use the <META> element to form an HTTP
| response header unless the HTTP-EQUIV attribute is present.
|
| An HTTP server may disregard any <META> elements that specify
| information controlled by the HTTP server, for example `Server',
| `Date', and `Last-modified'.
|

Regards,

-- 
Terry Allen  (terry@ora.com)   O'Reilly & Associates, Inc.
Editor, Digital Media Group    101 Morris St.
			       Sebastopol, Calif., 95472


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