1. A method of processing video data, the method comprising: performing a hypothetical reference decoder (HRD) operation, wherein the HRD operation determines conformance of a bitstream comprising encoded video data to a video coding standard or determines conformance of a video decoder to the video coding standard, wherein performing the HRD operation comprises: selecting an operation point under test, wherein a highest temporal identifier of a bitstream-subset associated with the operation point under test is less than a greatest temporal identifier present in the bitstream or a target set of layer identifiers of the bitstream-subset does not include all values of layer identifier syntax elements of the bitstream; determining, based on the highest temporal identifier, a first syntax element from among a first array of syntax elements in the bitstream, respective syntax elements in the first array of syntax elements specifying, for respective values of the highest temporal identifier, a maximum required size of a decoded picture buffer (DPB); determining, based on the highest temporal identifier, a second syntax element from among a second array of syntax element in the bitstream, respective syntax elements in the second array of syntax elements specifying, for respective values of the highest temporal identifier, a maximum allowed number of pictures preceding any picture in decoding order and succeeding that picture in output order; determining, based on the highest temporal identifier, a third syntax element from among a third array of syntax element in the bitstream, respective syntax elements in the third array of syntax elements specifying, for respective values of the highest temporal identifier, numbers, minus 1, of alternative coded picture buffer (CPB) specifications in the bitstream; and using the first, second, and third syntax elements in the HRD operation.