To summarize, Roy suggests adding a "header" attribute to <META>, so that
<meta header name="Expires" value="Tue, 04 Dec 1993 21:29:02 GMT">
would cause a server to generate
Expires: Tue, 04 Dec 1993 21:29:02 GMT
while it silently ignored <meta ...> tags without the header attribute, such as
<meta name="IndexType" value="Service">
FWIW, that certainly sits fine with me, but it might be possible to
consider more general schemes. So, for the sake of concreteness, I'll
propose a "purpose" attribute, whose value is a string defining the purpose
(or purposes) of this particular piece of meta-info. A few things which it
might be reasonable to have in a document are:
<meta purpose="header" name="Expires" value="Tue, 04 Dec 1993...">
<meta purpose="index" name="Type" value="service">
<meta purpose="index,header" name="Keywords"
value="metaindex, resource discovery, DTD syntax">
(The last one might be cleaner as <meta purpose="header" purpose="index"...>;
I did it as a single CDATA string assumed to contain a comma-separated list
of purposes simply to make it easier to type in manually).
Either Roy's scheme or mine is adequate to my current needs, of course, but
a purpose attribute may cope perhaps a little more gracefully when the
*third* use for explicit metainformation in HTML+ documents comes along...
...Roy Fielding ICS Grad Student, University of California, Irvine USA
<A HREF="http://www.ics.uci.edu/dir/grad/Software/fielding">About Roy</A>