| 释义 |
central office prefix Synonymous with central office exchange (COE) code. As defined by the North American Numbering Plan (NANP), the three-digit part of a telephone number that identifies the central office and the associated geographic carrier serving area (CSA).The central office (CO) prefix specifies the dialing pattern NXX, with N indicating that only digits 2–9 are allowed, as 0 or 1 would confuse the network, and X indicating that any digit is allowed. The complete telephone number takes the form NXX.xxxx. See also CSA and NANP. |