DICOM PS3.3 2019b - Information Object Definitions
C.8.8.14.11 Block and Compensator Precedence for Dosimetric Calculations

If Block Thickness (300A,0100) and Block Transmission (300A,0102) are present, Block Transmission shall have precedence for dosimetric calculations. If Compensator Transmission Data (300A,00EB) and Compensator Thickness Data (300A,00EC) are present, Compensator Transmission Data shall have precedence for dosimetric calculations.

DICOM PS3.3 2019b - Information Object Definitions