Nation-wide numbering plan

IN TELEPHONE language a numbering plan is exactly what the name implies, a plan or system of giving each telephone in a city, a town, or any geographical area an identity or designation which is different from that given every other telephone in this same area. This designation is the telephone number; it appears in the directory and in most cities on the telephone instrument itself. It is the address of the telephone in the telephone network. Just as it is essential for efficient postal and delivery service to have streets and house numbers clearly marked, it is important for good telephone service that the telephone numbering plan be such that it will be used with convenience and accuracy by the telephone customer.