diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 3fd67e606f..652580a804 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -20311,6 +20311,7 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
     (mtime) of each file in the log directory. By default, only superusers
     and members of the <literal>pg_monitor</literal> role can use this function.
     Access may be granted to others using <command>GRANT</command>.
+    Filenames beginning with a dot, directories, and other special files are not shown.
    </para>
 
    <indexterm>
@@ -20322,6 +20323,7 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
     default only superusers and members of the <literal>pg_monitor</literal> role
     can use this function. Access may be granted to others using
     <command>GRANT</command>.
+    Filenames beginning with a dot, directories, and other special files are not shown.
    </para>
 
    <indexterm>