(ok, it's not actually incomprehensible to me as i've been reading the source code, but it would certainly confusing to a new user).

--use-keyboxd is included in gpg --dump-options (fixed from mistaken --list-options, sorry!) , which means that commonly used tab-completion scripts will make it discoverable.

But when a novice user tries it they, get a strange note:

0 dkg@bob:~$ gpg --use-keyboxd --list-keys
gpg: Note: Please move option "use-keyboxd" to "common.conf"
0 dkg@bob:~$

Yes, it's interpretable if the user sifts through several different parts of the manpage and already understands common unix conventions; but it's noisy, and it seems likely to obscure real warnings that the user should be made aware of.

At the very least, GnuPG should hide --use-keyboxd from the output of --dump-options so that it's not discoverable through tab-completion. But perhaps it shouldn't be accessible from the command line at all, if it is intended to *only* be meaningful in ~/.gnupg/common.conf. If gpg needs to produce a warning when the option is given on the command line, while still interpreting it, the warning should identify the specific common.conf that the user needs to add it to (e.g. /home/dkg/.gnupg/common.conf), not just common.conf. Also, if use-keyboxd is already set in the appropriate common.conf maybe the warning isn't needed, as it should be a no-op?