diff --git a/runtime/doc/cmdline.txt b/runtime/doc/cmdline.txt
index 5564f5d..0c472bb 100644
--- a/runtime/doc/cmdline.txt
+++ b/runtime/doc/cmdline.txt
@@ -1,4 +1,4 @@
-*cmdline.txt*   For Vim version 8.2.  Last change: 2021 May 30
+*cmdline.txt*   For Vim version 8.2.  Last change: 2021 Aug 06
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -170,7 +170,12 @@
 				too.
 				When the result is a Float it's automatically
 				converted to a String.
-		See |registers| about registers.
+				Note that when you only want to move the
+				cursor and not insert anything, you must make
+				sure the expression evaluates to an empty
+				string.  E.g.: >
+					<C-R><C-R>=setcmdpos(2)[-1]<CR>
+<		See |registers| about registers.
 		Implementation detail: When using the |expression| register
 		and invoking setcmdpos(), this sets the position before
 		inserting the resulting string.  Use CTRL-R CTRL-R to set the