Airlines on the IOSA Registry will incorporate ongoing internal assessments using IOSA provisions in their Quality Assurance (QA) program. Before each renewal IOSA audit, the airlines will provide a Conformance Report (CR) to the Audit Organization. The information in the Conformance Report will be reviewed, verified and then form part of the overall IOSA assessment.
The E-IOSA process takes advantage of a significantly broader information base, thus providing increased value and continuity to the audit result.

This comes from the IOSA Enhanced IOSA Manual and true it is NOT regulatory. However, several of the countries we fly into and many we just fly over requires the company to be on the IOSA registry if we are operate in there airspace. It is not only flight operations that must conform in order to be on the registry. Dispatch, maintenance, ground handling, cargo loading, and ramp engineering are included in the IOSA program and are inspected every two years.
FOQUA stands for Flight Operations Quality Assurance and I do believe the company has a MOU with the FAA that established our program.