-Otherwise, this function always returns false."
- (and zmacs-regions zmacs-region-extent))
+Otherwise, this function always returns false.
+
+You should generally *NOT* use this in a menu item specification that you
+want grayed out when the region is not active. Instead, use this:
+
+ [ ... ... :active (region-exists-p)]
+
+Which correctly caters to the user's setting of `zmacs-regions'."
+ (and zmacs-regions zmacs-region-extent
+ (eq (current-buffer) (zmacs-region-buffer))))