A short while ago I wrote, Accessing vs Naming Models. I was unaware that @semantics had done a presentation called "A naming mechanism for the RDF model" which lists the RFCs: 3401, 3402, 3403 and 3404 (both interesting) and 3405.
There's also the older, yet still relevant THTTP specification for encoding resolution into a HTTP request.
I was aware of the Handle System, which is for documents, and has its own RFCs including RFC 3650.
I think I got rid of all the times I tried to type RFC and my hand spat out RDF.