RE: [xri] XRD feedback from Scott

["Scott Cantor" <cantor.2@osu.edu>]

Eran Hammer-Lahav wrote on 2009-05-28:
> I am not sure how much we need to spell out the relation between the
> transport caching directives to the document's expiration directives.
While
> they are used pretty much the same way, they have slightly different
> semantic meanings. In practice, if used over HTTP, the way the spec is
> written today is how it should be implemented (the earliest expiration
date
> of the two). Otherwise you violate either HTTP or XRD (or both).

It's true that caching policies are not the same as "validity" rules. In
other words, I think I would agree that they aren't semantically the same,
unless the XRD element is meant solely as a caching hint. So, no, I wouldn't
agree that you should just use the earliest for *validity* purposes. As an
example, if I get one that the HTTP layer says should be refetched, but is
still valid according to the XRD itself and I can't connect to the source
again to refresh it, should I rely on it?

-- Scott