; Add more detail to exchange-point-and-mark docstring

It didn't mention that exchange-point-and-mark-highlight-region
affects C-u C-x C-x too.

1 files changed, 9 insertions, 4 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 08ea5e27ab8..53658ac6d9b 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -7470,10 +7470,15 @@ This variable has no effect when Transient Mark mode is off."
 This command works even when the mark is not active, and it reactivates
 the mark unless `exchange-point-and-mark-highlight-region' is nil.
 
-If Transient Mark mode is on, a prefix ARG deactivates the mark
-if it is active, and otherwise avoids reactivating it.  If
-Transient Mark mode is off, a prefix ARG enables Transient Mark
-mode temporarily."
+If Transient Mark mode is on, a prefix ARG deactivates the mark if it is
+active, and otherwise avoids reactivating it.  However, if
+`exchange-point-and-mark-highlight-region' is nil, then using a prefix
+argument does reactivate the mark; effectively, when Transient Mark mode
+is on, setting `exchange-point-and-mark-highlight-region' to nil swaps
+the meanings of the presence and absence of a prefix argument.
+
+If Transient Mark mode is off, a prefix ARG enables Transient Mark mode
+temporarily."
   (interactive "P")
   (let ((omark (mark t))
         (region-was-active (region-active-p))