The core of the Single UNIX Specification, Version 3 is also IEEE Std 1003.1. The latest 2004 edition incorporates IEEE Std 1003.1-2001 and two technical corrigendum. IEEE Std 1003.1-2001 is a major revision and incorporates IEEE Std 1003.1-1990 (POSIX.1) and its subsequent amendments, and IEEE Std 1003.2-1992 (POSIX.2) and its subsequent amendments, combined with the core volumes of the Single UNIX Specification, Version 2. It is technically identical to The Open Group, Base Specifications, Issue 6; they are one and the same documents, the front cover having both designations. The final draft achieved 98% approval by the IEEE ballot group and was officially approved by the IEEE-SA Standards Board on December 6th 2001.
During 2002, Technical Corrigendum 1 was developed. It was approved by the IEEE-SA Standards Board on December 11th 2002. In 2004 , IEEE Std 1003.1-2001/Cor 2-2004 was approved, and IEEE Std 1003.1 is officially designated as including IEEE Std 1003.1-2001, IEEE Std 1003.1-2001/Cor 1-2002. and IEEE Std 1003.1-2001/Cor 2-2004.Register to read or download the html online copy of IEEE Std 1003.1.