diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index e432bb015a..cba7292f98 100644
--- a/doc/src/sgml/backup.sgml
+++ b/doc/src/sgml/backup.sgml
@@ -691,11 +691,9 @@ test ! -f /mnt/server/archivedir/00000001000000A900000065 && cp pg_wal/0
     system crashes before the server makes a durable record of archival success,
     the server will attempt to archive the file again after restarting (provided
     archiving is still enabled).  When an archive library encounters a
-    pre-existing file, it may return <literal>true</literal> if the WAL file has
+    pre-existing file, it should return <literal>true</literal> if the WAL file has
     identical contents to the pre-existing archive and the pre-existing archive
-    is fully persisted to storage.  Alternatively, the archive library may
-    return <literal>false</literal> anytime a pre-existing file is encountered,
-    but this will require manual action by an administrator to resolve.  If a
+    is fully persisted to storage.  If a
     pre-existing file contains different contents than the WAL file being
     archived, the archive library <emphasis>must</emphasis> return
     <literal>false</literal>.