0-9 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Signaling in which dual tone multifrequency (DTMF) signals or pulse trains are transmitted to a switching center. Note 1: Rotary dials produce pulse trains. Keypads may produce either DTMF signals or pulse trains. Note 2: Dial signaling traditionally refers to pulse trains only. (188)