This question led to a new package:
I know that
cleveref is not compatible with
showonlyrefs as it says in the
cleveref manual. But I have a book-length document that depends on
showonlyrefs and I would like to start using
cref without having to go back and add a
\notag to each of the equations that I do not want to assign a number to.
Is there a known hack or an easy way to use
cref? I have recently begun to appreciate the power of
cleveref and would like to use it without going back and changing each and every one of my equations.