Data expansion:

1. Postal code:

It is a coding method that a country or region divides the whole country in order to realize the automation of mail sorting and the digitalization of postal network and speed up the delivery of mail. Postal coding system has become one of the standards to measure a country's communication technology and postal service level. Postal code usually consists of Arabic numerals, which represents the special code of the post office that delivers mail, and is also the communication code between residents and units within the delivery range of the post office.

2. Japan Post:

The new postal code system was put into use on February 2nd, 1998. The purpose of developing the system is to meet the needs of the expanding postal mechanization operation, improve the operation efficiency and ensure to provide users with stable, cheap and high-quality services. Its main features are as follows: the postal code has 7 digits, and characters are used between the first three digits and the last four digits. At present, all text structures use numbers; The connection between the old and new postal code systems; Three or five digits in the old code are the first digits in the new code.