one or more numberingplan area codes (NPA codes, or area codes), consisting of three digits that are prefixed to each local telephonenumber having seven
intermediary telephone operators. Expanding this technology for national use required a comprehensive and universal, continent-wide telephonenumberingplan. The
Dallas (/ˈdæləs/) is a city in the U.S. state of Texas and the most populous city in the Dallas–Fort Worth metroplex, the most populous metropolitan area
The number format follows the N11 code for a group of short, special-purpose local numbers as designated in the North American NumberingPlan. The telephone