!               Annotate current level: you can enter any string.
                        This annotation is then listed in the dungeon 
                        overview (Ctrl-O) and also shown whenever you 
                        enter that level again. If you use this command 
                        when standing on a staircase, you may also 
                        annotate the level that staircase leads to.
                        Should your annotation contain an exclamation
                        mark (!), you will be prompted before entering
                        the level. An empty string clears any annotation.