feh(1): Excplicitly state that --geometry does not enforce its limitations

man/feh.pre

@@ -283,6 +283,9 @@ like 640x480 with optional +x+y window offset.
 Note that larger images will be zoomed out to fit, but you can see them at 1:1
 by clicking the zoom button.
 .
+Note that this option does not enforce the geometry, changing it by a tiling
+WM or manually is still possible.
+.
 .It Cm -Y , --hide-pointer
 .
 Hide the pointer