The scheme of telephone numbers for 19 countries in the area officially known as World Zone 1, which excludes Mexico, and includes the Continental United States, Hawaii, Canada, Puerto Rico, the Virgin Islands, and parts of the Caribbean. AT&T and Bell Telephone Laboratories established the NANP in 1947 as a means of integrating the area codes and central office (CO) exchange codes in the area loosely known as North America.The North American Numbering Council (NANC), chartered in 1995, is an impartial body with oversight responsibility for the NANP. The Canadian Radio-television and Telecommunications Commission (CRTC) is responsible for the numbering plan in that country. In the Caribbean, some of the various governments delegate administration, while others retain that responsibility. In the United States, the Federal Communications Commission (FCC) has appointed NeuStar, a commercial enterprise, as the NANP administrator.The U.S. number format comprises fixed-length, ten-digit national numbers, which fit into the international NPA dialing scheme (+CC.NPA.NXX.xxxx). See also area code, AT&T, Bell Labs, central office exchange code, CRTC, FCC, NANC, NeuStar, and NPA.