provide guidance for intentionally non-dereferencable URIs

[dret]

11 provides good guidance in terms of probably bets avoiding relative URIs. what about also providing guidance for people who intentionally want to use non-dereferencable URIs for type or instance? should we add some guidance for this as well? we had some discussion around tag URIs in #11 and there are other possibilities as well. but the main question is: if somebody never intends to use dereferencable URIs for type or instance, should we mention that and provide guidance?

[mnot]

Is this a duplicate of #13?

[pimterry]

I think this is indeed a duplicate

[mnot]

Closing for now; if there's a reason to distinguish it we can reopen.