1. If the beam steel bars start with B, it means the lower layer of steel bars of the beam, and if it starts with T, it means the upper layer of steel bars.

2. If centralized annotation and in-situ annotation are different, in-situ annotation will take precedence.

3. If the steel bars are marked on the upper side of the beam, it means that the upper steel bars of the beam will be marked in situ. If there is no mark below, it will be marked centrally. In the same way, if the mark is on the lower side, then the lower layer of steel bars representing the beam will be marked in situ, and if there is no in situ mark in the upper layer, it will be marked in centralized way.