…..or set higher requirements than what is regulated by the authority.
e.g. my airline decided to raise the circling minima to 3000 meters visibility given the fast speed of the -800.
I did fly a CAT C a/c and the promulgated minimum vis was 2400m, as now. The local XAA FOI did a calculation regarding the radius of a continuos turn from downwind to finals. He concluded that 2400m was not enough to keep the runway in sight at the spacing required to make a rate 1 turn onto finals. He enforced 3600m (CAT D) on the airline. We disagreed by performing in the sim and found a downwind spacing of 2400m to be sufficient for the turn. No success. His opinion was that 2400m vis at 500' agl was not healthy and that was it. Minima are just that.