ISO/IEC 5218 Information technology — Codes for the representation of human sexes is an international standard that defines a representation of human sexes through a language-neutral single-digit code. It can be used in information systems such as database applications.
The four codes specified in ISO/IEC 5218 are:
The standard specifies that its use may be referred to by the designator "SEX".
The standard explicitly states that no significance is to be placed on the fact that male is encoded as 1 and female as 2. The encoding merely reflects existing practice in the countries that initiated this standard.
ISO/IEC 5218 was created by ISO's Data Management and Interchange Technical Committee, proposed in November 1976, and updated in July 2004.
This standard is used in several national identification numbers. For example, the first digit of the French INSEE number, the first digit of the Republic of China national identification card (Chinese: 中華民國國民身分證) are based on ISO/IEC 5218 values.