The drawing is proprietary. But, since there are no other feature control frames on the entire print except for the flatness callout in the same view as the BASIC dimension... I believe someone thought they could get away with it.
Flatness controls form but not usually location or orientation.
I've got a drawing where they're using the Flatness feature control frame to locate a surface to a hole. They've made the related dimension BASIC.
Can you really do that?