diff --git a/runtime/doc/usr_11.txt b/runtime/doc/usr_11.txt
index bf09d2e..54f0075 100644
--- a/runtime/doc/usr_11.txt
+++ b/runtime/doc/usr_11.txt
@@ -1,4 +1,4 @@
-*usr_11.txt*	For Vim version 8.1.  Last change: 2019 Feb 04
+*usr_11.txt*	For Vim version 8.1.  Last change: 2019 Apr 28
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -205,6 +205,13 @@
       NEWER than swap file! ~
 
 
+NOTE that in the following situation Vim knows the swap file is not useful and
+will automatically delete it:
+- The file is a valid swap file (Magic number is correct).
+- The flag that the file was modified is not set.
+- The process is not running.
+
+
 UNREADABLE SWAP FILE
 
 Sometimes the line