-found for the user ID, then nothing is done. `a' may be used in place
-of `update-authorized_keys'.
+found for the user ID, then nothing is done. This command will exit
+with a status of 0 if all user IDs were found to be acceptable, 2 if
+all the user IDs were found to be unacceptable (ie. with keys removed
+from the authorized_keys file), and 1 otherwise. `a' may be used in
+place of `update-authorized_keys'.