+L<xapian-compact(1)> which is required to work with the
+rest of the public-inbox search code.
+
+This command is rarely needed for active inboxes.
+
+Using the C<--compact> option of L<public-inbox-index(1)>
+is recommended, instead, and only when doing a C<--reindex>.
+
+=head1 OPTIONS
+
+=over
+
+=item --all
+
+Compact all inboxes configured in ~/.public-inbox/config.
+This is an alternative to specifying individual inboxes directories
+on the command-line.
+
+=item --blocksize
+
+=item --no-full
+
+=item --fuller
+
+These options are passed directly to L<xapian-compact(1)>.
+
+=back