+@defvar window-size-change-functions
+This variable holds a list of functions to be called if the size of any
+window changes for any reason. The functions are called just once per
+redisplay, and just once for each frame on which size changes have
+occurred.
+
+Each function receives the frame as its sole argument. There is no
+direct way to find out which windows changed size, or precisely how;
+however, if your size-change function keeps track, after each change, of
+the windows that interest you, you can figure out what has changed by
+comparing the old size data with the new.
+
+Creating or deleting windows counts as a size change, and therefore
+causes these functions to be called. Changing the frame size also
+counts, because it changes the sizes of the existing windows.
+
+It is not a good idea to use @code{save-window-excursion} in these
+functions, because that always counts as a size change, and it would
+cause these functions to be called over and over. In most cases,
+@code{save-selected-window} is what you need here.
+@end defvar
+