The
Single UNIX Specification (
SUS) is the collective name of a family of standards for
computer operating systems, compliance with which is required to qualify for to use the "
UNIX" trademark. The core specifications of the SUS are developed and maintained by the
Austin Group, which is a joint working group of
IEEE, ISO JTC 1 SC22 and
The Open Group. If an operating system is submitted to The Open Group for certification, and passes conformance tests, then it is termed to be compliant with a UNIX standard such as UNIX 98 or UNIX 03.