A video data processing procedure, the method comprising: determining whether one or more additional nesting enhancement information SEI messages encapsulated by a scalable nesting SEI message are applicable to a default bit sub-stream of a data stream. bits of encoded video, the default bit sub-stream being an operating point representation of an operating point defined by a layer identifier and a temporary identifier, the layer identifier and the temporary identifier being specified in a header of the network abstraction layer unit, NAL, of a SEI NAL unit that encapsulates the scalable nesting SEI message; and when the one or more nesting SEI messages are applicable to the default bit sub-stream, use the one or more nesting SEI messages in an operation in the default bit sub-stream, in which the determination of whether The one or more nesting SEI messages encapsulated by the scalable nesting SEI messages are applicable to the default bit sub-stream is based at least in part on a syntactic element in the scalable nesting SEI message, in which the syntactic element It is not in any of the nesting SEI messages.