We are keen both to credit contributors and ensure everyone has signed the Python CLA, but we don't have reliable records.

We have always made a reasonable job of crediting contributors in ACKNOWLEDGMENTS. We sometimes make a judgement that a contribution is small enough (tidy up dead files, tweak to CI #261) that the PSF process is not necessary, but accord a mention in ACKNOWLEDGMENTS. Sometimes contributors who sign the CLA do not trouble to be in ACKNOWLEDGEMENTS #273.

The records created when we send people to sign the CLA at https://www.python.org/psf/contrib/contrib-form/ are not in practice accessible when we need to check them, now that bugs.python.org is frozen (only CLA records made before the freeze can be checked). See psf/gh-migration#25. GitHub name is the primary key for this process but people deserve a name too, and in case we move.

I propose we make ACKNOWLEDGMENTS record CLA status, and a date when we (last) checked. I think there might be 3 kinds of positive status:
A. at the CPython API (or visible in a CPython PR) <date>.
B. known from bugs.python.org at <date>.
C. self-reported at <date>.
Blank means we don't know but maybe X = we looked on <date> but haven't found a record.