Mandatory Presentation [was: textured backgrounds]

Marc Salomon (marc@library.ucsf.edu)
Sun, 22 Jan 95 14:26:00 EST

If publishers are going to insist on a certain rendering style as essentially
a condition use for an object as Rob Raisch suggests, then we should deal with
that condition of use the same way we deal with other conditions of use, such
as a mandatory copyright popup.

This ends up as less of a style issue, but more of an issue of however
conditions of use are represented in the protocol. One way to do this is with
a combination of the Mandatory: and Link: headers in HTTP. The publisher would want to create a link for each condition of use, and require the client grok
each Mandatory condition:

<HEAD><TITLE>See Me My Way Or Else</TITLE>
<LINK REL="style" HREF="http://control.com/corporate_style">
<LINK REL="copyright" HREF="http://control.com/corporate_copyright">
<META HTTP-EQUIV="Mandatory" CONTENTS="Link" REL="style">
<META HTTP-EQUIV="Mandatory" CONTENTS="Link" REL="copyright">
</HEAD>

which in the protocol is:

Link: REL=style HREF=http://control.com/corporate_style
Link: REL=copyright HREF=http://control.com/corporate_copyright
Mandatory: Link REL=style, REL=copyright

This breaks the BNF for Mandatory (which seems to allow only other HTTP field
names) by decreasing its granularity. Instead of pointing to a single field,
Mandatory should be able to reference certain instances (REL's or REV's) of
multiple-occuring fields. It would be desirable to Mandate certain Links and
treat others as informative. This would also add two more well-known REL's
(style and copyright) to Link.

-marc