DICOM allows multiple VOI and presentation Lookup Tables (LUTs) in images, and the user may select whichever they require. These properties provide that choice, and the value 0 may be used to disable a particular type of LUT. Only one Modality LUT is allowed, so the only meaningful values for ModalityLUT are 0 and 1, but the other two may range from 0 to the number of such LUTs in the image. Value beyond the available range are treated as 0. The default values are all 1, indicating that the first table of each type, if present, should be used.