They are usually listed in the statement of special inspections drawn up by the EOR (engineer of record) or in the project specifications.

The specific WPS used for welder qualification would or could be construed to be part of the welding documentation package when the project specifications requests that the welding documents be submitted for review.

I would want to see the specifics of the welder qualification tests if I was asked to review the welding documentation.

Best regards - Al