How about that? Remember the discussions from months ago (“WS-Web” and “Names and Addresses – a different view”) about the identity of resources and their relationship to HTTP URIs? I just read this story about Netscape taking down the resource representation of the RSS 0.91 DTD Schema at the end of the http://my.netscape.com/publish/formats/rss-0.9.dtd URI. They brought it back but with an expiration day in July. I may have missed it but does RFC 2616 say anything about URI expiration?
Yes, agents around the world should cache the resource’s representation; they shouldn’t retrieve it every time it is used; they should be implemented defensively against the brittle, loosely coupled nature of the Web. Still, the resource’s representation is retrieved 4M times per day. Now, if the resource was associated with a protocol-independent URI that could be retrieved/searched/indexed irrespective of the protocol/technology used to access it, we wouldn’t have this problem.
I think the coupling of identity with protocol semantics makes it more difficult to program defensively.
Please, be gentle in your comments :-)