urn:solid: for prototyping predicates

Hey all,

Quick note following yesterday’s CG call.  Michiel and I were brainstorming
around using "urn:solid" as a simple way to prototype predicates while
waiting for proper HTTP URIs to be minted.

It could be a handy trick for rapid app development, especially in
lighter-weight stacks like Solid Lite.

Jesse raised a valid point in opposition, that http URIs (e.g. at
w3id.org) might
be a better long-term approach for structured vocabularies,

But for quick iterations this feels like a good fit.

In any case, I wrote up a short spec draft here if you're curious:

https://solid-lite.github.io/urn-solid/

Would love any thoughts!

Cheers,
Melvin