Pat Hayes on URI ambiguity

In this excellent thread on SWBPD list, Pat Hayes makes a good point again. URI are ambiguous identifiers, and can be used for more than one referent, hence bearing different or conflicting semantics in different declaration or processing contexts. Just as any name.
Now, what I pushed lately here and there is that different URIs can have the same referent, but describe it differently from different perspectives. Hubjects are formalizations of referents as binding blank nodes. Those two points seem dual and complementary.
Where I differ with Pat is when he says that context, which indeed provides disambiguation of the referent, and is implicitly defined by rules of a given community, a given protocol, should stay this way. In other words, it can't, or should not, be formalized as an object, jusque like in ordinary conversation : the context is effective without being explicit. I think context (or perspective) could and should be declared formally ...