Eric Abrahamsen <eric@ericabrahamsen.net> writes:
> Theoretically, reducing `gnus-registry-max-entries' is what you do to
> trim it back! What's your value of `gnus-registry-track-extra'? That
> might contribute to a larger file size.

The relevant settings appear to be:

(setq gnus-registry-max-entries          20000
      gnus-registry-split-strategy       nil
      gnus-registry-use-long-group-names t
      gnus-registry-track-extra          '(recipient))

I’m reasonably sure that gnus-registry-split-fancy-with-parent is the
only thing I’m using it for. Not sure why I put ‘recipient’ in there.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | Those who in their youth did not live
http://nwalsh.com/            | in self-harmony, and who did not gain
                              | the true treasures of life, are later
                              | like long-legged old herons standing
                              | sadly by a lake without fish.--The
                              | Dhammapada