Other forms such as American Sign Language (ASL), Morse code, typing braille, etc. are clearly forms of verbal behavior and can, therefore, become verbal stimuli. All of these forms of verbal behavior can easily be classified into analogous elementary relationships. In fact, in three of the elementary relationships, the form of the response is unspecified and there is no need to discuss analogous categories. These three are the intraverbal, tact, and mand.