Ask a question about verticality representation

The above marking method is generally not allowed for verticality markings. The corners of the arrows should be vertical. This picture indicates that the line or surface pointed by the arrow (cannot be determined from this picture) is relative to the first The verticality of datum A and second datum B is 0.4mm, and the tolerance zone is 0.4mm. Because the markings on the surfaces of different parts have different meanings, this picture cannot explain it specifically.