Obsolete/retired or obsolete/out of circulation, all the same to me.

Either way, it differentiates between chips from clubs that no longer exist, and chips that are not "circulated" on the tables but are still official chips of a functioning establishment.

Seems to me that a collector would make a primary distinction between chips from dark casinos (obsolete), and those from existing casinos.

If you can't cash it in, it's "function" is obsolete. If you can cash it in, even if it's insane to do so because its collector value exceeds its "face" value, it ain't obsolete.

I also think that it's terminology that the club or hobby could agree on, since the distinction is not a matter of opinion, but one of fact.