A telephone number or phone number is a sequence of digits used to call from one telephone line to another in a public switched telephone network(PSTN). When telephone numbers were invented, they were short — as few as one, two or three digits — and were given orally to a switchboard operator. As phone systems have grown and interconnected to encompass the world, telephone numbers have become longer.
A telephone number or phone number is a sequence of digits used to call from one telephone line to another in a public switched telephone network. When telephone numbers were invented, they were short — as few as one, two or three digits — and were given orally to a switchboard operator. As phone systems have grown and interconnected to encompass the world, telephone numbers have become longer. In addition to telephones, they now access other devices, such as computers and fax machines.
Telephone numbers must not be stored using numerical data types.
The format of telephone numbers internationally follows ITU-T Recommendation E.164, described here.
This is a useful reference for people creating software to handle telephone numbers: Falsehoods Programmers Believe About Phone Numbers.
