standard ambiguous code (mobile com) (SAC)
The Standard Ambiguous Code (SAC) defines the letters assigned to a specific numeric key on the cell phone keypad. This assignment was standardized by the International Telecommunication Union( ITU).
For example, in the SAC code, numeric key 2 on the cell phone keypad is assigned the letters A, B, C, and numeric key 3 is assigned the letters D, E, F, and so on. Most of the numeric keys are assigned three letters; only numeric keys 7 and 9 are assigned four letters.
The letters are activated by pressing the same number key several times. If the letter "S" is called, then the number key 7 must be pressed four times. The letter entries are used for the Short Message Service( SMS) and for the name entries in the phone book. To limit the multiple presses, there is a text input help like T9(Text on 9 Keys) with which the input is reduced to a single keystroke per letter.