-TT_ID [-32768 to 32767]
-Select thing type to manipulate by argument as ID. If argument is < 0 or > 255,
-change it to the lowest unused thing type ID. If thing type of ID does not exist
-yet, create it with default name "(none)", corpse ID equal to the new thing
-type's ID, symbol "?", and remaining thing type attributes to 0.
+TT_ID [-1 to infinity]
+Select thing type to manipulate by argument as ID. If argument is < 0, change it
+to the lowest unused thing type ID. If thing type of ID does not exist yet,
+create it with default name "(none)", corpse ID equal to the new thing type's
+ID, symbol "?", and remaining thing type attributes to 0.