Q

1. One of the two letters, along with Z, that traditionally did not appear on a telephone dial or keypad. The thought was that Q could be confused with O, and that Z could be confused with 2. Q now appears with P, R, and S on number 7. Alphanumeric dialing was, and remains, a North American practice. Telephones in most other countries do not sport letters. 2. Q interface or Reference Point Q in ISDN. See Reference Point Q.

• Figure P-4
• Figure P-5
• Figure P-6
• Figure P-7
• Figure P-8
• Figure Q-1
• Figure R-1
• Figure R-2
• Figure S-1
• Figure S-10
• Figure S-11
• Figure S-12
• Figure S-2
• Figure S-3
• Figure S-4
• Figure S-5
• Figure S-6
• Figure S-7
• Figure S-8
• Figure S-9
• Figure T-1
• Figure T-2
• Figure T-3
• Figure T-4
• Figure T-5