RE: Caching paragraph, #issue-html-nsdoc

> Something in that direction seems reasonable, but that 
> particular wording conflicts with our recent decision on 
> #issue-conformance-labels:

It might be modified to something like:

[[
Some standard namespace documents, such as the HTML [@@ref] namespace
document have very many references to them.  If GRDDL aware agents were
to retrieve these documents every time they processed a document
referring to them, the servers serving those documents could become
overloaded.  GRDDL aware agents therefore should retrieve such documents
on every reference and should retain some local memory of the
transformations those documents indicate should be applied.  To avoid
misrepresentation of published information, GRDDL aware agents should
ensure that this local memory is up to date.
]] 

Brian