-If \c{expand} is set to \cw{FALSE}, then the game's tile size will
-never go over its preferred one. This is the recommended approach
-when opening a new window at default size: the game will use its
-preferred size unless it has to use a smaller one to fit on the
-screen.
-
-If \c{expand} is set to \cw{TRUE}, the mid-end will pick a tile size
-which approximates the input size \e{as closely as possible}, and
-will go over the game's preferred tile size if necessary to achieve
-this. Use this option if you want your front end to support dynamic
-resizing of the puzzle window with automatic scaling of the puzzle
-to fit.
+Use \c{user_size} to indicate whether \c{*x} and \c{*y} are a
+requested size, or just a maximum size.
+
+If \c{user_size} is set to \cw{TRUE}, the mid-end will treat the
+input size as a request, and will pick a tile size which
+approximates it \e{as closely as possible}, going over the game's
+preferred tile size if necessary to achieve this. The mid-end will
+also use the resulting tile size as its preferred one until further
+notice, on the assumption that this size was explicitly requested
+by the user. Use this option if you want your front end to support
+dynamic resizing of the puzzle window with automatic scaling of the
+puzzle to fit.
+
+If \c{user_size} is set to \cw{FALSE}, then the game's tile size
+will never go over its preferred one, although it may go under in
+order to fit within the maximum bounds specified by \c{*x} and
+\c{*y}. This is the recommended approach when opening a new window
+at default size: the game will use its preferred size unless it has
+to use a smaller one to fit on the screen. If the tile size is
+shrunk for this reason, the change will not persist; if a smaller
+grid is subsequently chosen, the tile size will recover.