620:/lib/library.c (/lib/library.c)
(public void) library_classify_unavailable_shelf_hook(string shelf)
/*
 * Function name: library_classify_unavailable_shelf_hook
 * Description:   Redefine this to alter the message given when a
 *                user attempts to classify a book under a nonexistant
 *                shelf
 * Arguments:     string shelf - the shelf name
 */ 
