* lisp/simple.el (use-empty-active-region): Doc tweak.
There's only one region (bug#16513).
(defcustom use-empty-active-region nil
"Whether \"region-aware\" commands should act on empty regions.
-If nil, region-aware commands treat empty regions as inactive.
+If nil, region-aware commands treat the empty region as inactive.
If non-nil, region-aware commands treat the region as active as
long as the mark is active, even if the region is empty.