Default: none
+=item extindex.<name>.topdir
+
+The directory of an external index. See
+L<public-inbox-extindex(1)> for more details.
+
+=item extindex.<name>.url
+
+Identical to L</publicinbox.E<lt>nameE<gt>.url>, but for
+external indices
+
+=item extindex.<name>.coderepo
+
+Identical to L</publicinbox.E<lt>nameE<gt>.coderepo>, but for
+external indices. Code repos may be freely associated with
+any number of public inboxes and external indices.
+
=back
=head2 NAMED LIMITER (PSGI)
=head1 DESCRIPTION
-FIXME: behavior not finalized It should probably write to the
-config file the first time --all is used.
-
public-inbox-extindex creates and updates an external search and
overview database used by the read-only public-inbox PSGI (HTTP),
NNTP, and IMAP interfaces. This requires either the
=head1 CONFIGURATION
-... TODO, see L<public-inbox-index(5)>
+public-inbox-extindex does not currently write to the
+L<public-inbox-config(5)> file, configuration may be entered
+manually. The extindex name of C<all> is a special case which
+corresponds to indexing C<--all> inboxes. An example for
+C<--all> is as follows:
+
+ [extindex "all"]
+ topdir = /path/to/extindex_dir
+ url = all
+ coderepo = foo
+ coderepo = bar
+
+See L<public-inbox-config(5)> for more details.
=head1 ENVIRONMENT