webid predicate

Hi All

This was raised a few years back, but not resolved.

We dont have a predicate for webid itself.

It would be useful in heterogeneous systems to write

[]  :webid <myPreferredURI> .

Let me give you a use case.  In th popular web 2.0 federated microblogging
service, mastodon, you are allowed to specify key value pairs to tie to
your profile (nice!).  So what would be valuable would be to add a webid,
with the appropriate label so that it is possible to follow your nose to
the linked data universe.

The question is where to put it.

Strangely enough webid doesnt actually have an identity vocab.  Should we
start one perhaps?

It could also go on the cert ontology, tho not quite the right place.

It could also go in the solid vocab, which seems kind of OK.  For various
reasons it's better to have it on one place, I think.

As a stop gap we could use the preferredURI predicate, tho unsure that's
ideal ..

Any thoughts?