doc: Clarify release notes item

Reported-by: Justin Pryzby <pryzby@telsasoft.com>

diff --git a/doc/src/sgml/release-12.sgml b/doc/src/sgml/release-12.sgml
index 3d7ce9fa1026b2384fa7fcd18e3c248d34d31ec2..43b1b81ad82bef9b1c959eab77514b04b61ea969 100644 (file)
--- a/doc/src/sgml/release-12.sgml
+++ b/doc/src/sgml/release-12.sgml
@@ -2267,7 +2267,8 @@ Author: Peter Eisentraut <peter@eisentraut.org>
 
       <para>
        Modifications of catalogs' <literal>reloptions</literal> and
-       autovacuum settings are now supported.
+       autovacuum settings are now supported.  (Setting <xref
+       linkend="guc-allow-system-table-mods"/> is still required.)
       </para>
      </listitem>