A computing device obtains a Network Abstraction Layer (NAL) unit header of a NAL unit of the multi-layer video data. The NAL unit header comprises a layer identifier syntax element having a value that specifies an identifier of a layer of the NAL unit. The layer identifier syntax element comprises a plurality of bits that represent the value within a defined range of values. A requirement of the bitstream conforming to a video coding standard is that the value of the layer identifier syntax element is less than the maximum value of the range of values.