icture parameter set RBSP and SVC sequence parameter set RBSP that are in effect are specified in clause G.7.4.1.2.1. When an SEI NAL unit contains an SEI message with payloadType in the range of 24 to 35, inclusive, it shall not contain any SEI message with payloadTyp less than 24 that is not included in a scalable nesting SEI message, and the first SEI message in the SEI NAL unit shall have payloadTyp in the range of 24 to 35, inclusive. When an SEI NAL unit contains an SEI message with payloadType equal to 24, 28, or 29, it shall not contain any SEI message with payloadT not equal to 24, 28, or 29. When a scalable nesting SEI message (payloadType is equal to 30) is present in an SEI NAL unit, it shall be the only SEI message in the SEI NAL unit. The semantics for SEI messages with payloadType in the range of 24 to 35, inclusive, are specified in the following. G.13.2.1 Scalability information SEI message semantics The scalability information SEI message provides scalability information for subsets of the bitstream. In the following specification of this clause, a VCL NAL unit of a primary coded picture is also referred to as primary coded VCL NAL unit and a VCL NAL unit of a redundant coded picture is also referred to as redundant coded VCL NAL unit. A scalability information SEI message shall not be included in a scalable nesting SEI message. A scalability information SEI message shall not be present in access units that contain primary coded VCL NAL units with IdrPicFlag equal to 0. The set of access units consisting of the access unit associated with the scalability information Rec. ITU-T H.264 (01/2012) SEI message and all succeeding access units in decoding order until, but excluding, the next access unit that does not contain any primary coded VCL NAL unit with IdrPicFlag equal to 0 (if present) or the end of the bitstream (otherwise) is referred to as the target access unit set. The scalability information SEI message applies to the target access unit set. The scalability information SEI message provide