How to distinguish coarse teeth from fine teeth in a thread mark?

Thread marking is clearly stipulated in the standard, which is a standard marking method. For example, there are several marking methods for thread diameter 16. If it is coarse thread, mark it as M 16-7H(M 16 represents the internal thread of the thread specification and is coarse thread, 7H represents the thread matching accuracy grade) or M 16-7H.

For example, there are several marking methods for thread diameter 16. If it is a fine thread, it is marked as m16 * 1.5-7H (m16 represents the internal thread of the thread size,1.5 represents the pitch, but it can also be other values, and 7h represents the thread matching accuracy level) or m 65438.