A device determines, based at least in part on a syntax element in a supplementary enhancement information message (SEI) of scalable nesting encapsulated by means of a network abstraction layer unit (NAL) , for its acronym in English), if a nested SEI message encapsulated by means of the scalable nesting SEI message is applicable to a substream of bits by default. The default bit undercurrent is a representation of the operating point of a defined operating point by means of a layer identifier specified in a header of the NAL unit of the SEI NAL unit and a temporary identifier specified in the header of the NAL unit. When the nested SEI message is applicable to the default bit undercurrent, the device uses the nested SEI message in an operation over the default bit undercurrent.