Wikimedia Bugzilla is closed!

Having a parameter which allows yes and no sounds not easy to use.

  coprimary           - Whether to return only primary coordinates (``yes''), secondary (``no'') or both (``yes|no'')
                        Values (separate with '|'): yes, no
                        Default: yes

It is possible to change this param to a three state param like apfilterredir from list=allpages?

  apfilterredir       - Which pages to list
                        One value: all, redirects, nonredirects
                        Default: all


Something like:

 coprimary           - Whether to filter on primary coordinates
                        Values (separate with '|'): all, primary, nonprimary
                        Default: primary

This is beta, so no problem with a breaking change, maybe name the param filterprimary and deprecate primary or remove it.