Document ~/.fehbg a bit more precisely

man/feh.pre

@@ -962,14 +962,17 @@ Unless you pass the
 option, it will write a script to set the current background to
 .Pa ~/.fehbg .
 So to have your background restored every time you start X, you can add
-.Qq sh ~/.fehbg &
+.Qq ~/.fehbg &
 to your X startup script
 .Pq such as Pa ~/.xinitrc .
-As of
+Note that
+.Pq unless the wallpaper is set via the menu
 .Nm
-2.13, this script is executable, so
-.Qq ~/.fehbg &
-will work as well.
+saves the files and directories it was passed on the commandline, not the
+files which actually ended up as wallpaper.
+So, if you have randomization enabled,
+.Pa ~/.fehbg
+may set different wallpapers on each execution.
 .
 .Pp
 .