diff --git a/runtime/doc/vim9.txt b/runtime/doc/vim9.txt
index 34048ec..4e8016c 100644
--- a/runtime/doc/vim9.txt
+++ b/runtime/doc/vim9.txt
@@ -1082,7 +1082,9 @@
 Vim default value, like with: >
 	:set cpo&vim
 One of the effects is that |line-continuation| is always enabled.
-The original value of 'cpoptions' is restored at the end of the script.
+The original value of 'cpoptions' is restored at the end of the script, while
+flags added or removed in the script are also added to or removed from the
+original value to get the same effect.  The order of flags may change.
 
 							*vim9-mix*
 There is one way to use both legacy and Vim9 syntax in one script file: >