rder (ASO): A decoding order of slices in which the macroblock address of the first macroblock of some slice of a slice group within a layer representation may be less than the macroblock address of the first macroblock of some other preceding slice of the same slice group within the same layer representation or in which the slices of a slice group within a layer representation may be interleaved with the slices of one or more other slices groups within the same layer representation. G.3.2 associated NAL unit: A NAL unit that directly succeeds a prefix NAL unit in decoding order. G.3.3 B slice: A slice that may be decoded using intra-layer intra prediction or inter prediction using at most two motion vectors and reference indices to predict the sample values of each block. G.3.4 base layer: A bitstream subset that contains all NAL units with the nal_unit_type syntax element equal to 1 and 5 of the bitstream and does not contain any NAL unit with the nal_unit_type syntax element equal to 14, 15, or 20 and conforms to one or more of the profiles specified in Annex A. G.3.5 base quality layer representation: The layer representation of the target dependency representation of an access unit that is associated with the quality_id syntax element equal to 0. G.3.6 bitstream subset: A bitstream that is derived as a subset from a bitstream by discarding zero or more NAL units. A bitstream subset is also referred to as sub-bitstream. G.3.7 bottom macroblock (of a macroblock pair): The macroblock within a macroblock pair that contains the samples in the bottom row of samples for the macroblock pair. For a field macroblock pair, the bottom macroblock represents the samples from the region of the bottom field or layer bottom field of the frame or layer frame, respectively, that lie within the spatial region of the macroblock pair. For a frame macroblock pair, the bottom macroblock represents the samples of the frame or layer frame that lie within the bottom half of the spatial region of the macroblock pair. G.3.8 coded slice 