Original discussion and need is within datalad/issues/7038 -- we had been using annex find and annex findref with --copies 0 to simply force those two commands to return information for all keys used in the current tree, regardless of their local presence.

Unfortunately as that issue shows, adding --copies 0 results in significant run time penalty over a run without it, or some different invocation with similar (albeit not as generic, since would miss keys without size) --largerthan -1.

I found no other way to make find (or findref) to do what is needed. So I felt that may be it does need some additional option, or may be some special ad-hoc value for some of the possible "fast" expressions (like --largerthan idonotcare).

done; added --anything (and --nothing). --Joey