ving syntax and semantics as specified by the entity identified by the ITU-T T.35 country code and terminal provider code. D.2.6 User data unregistered SEI message semantics This message contains unregistered user data identified by a UUID, the contents of which are not specified by this Recommendation International Standard. unid_iso_iec_11578 shall have a value specified as a UUID according to the procedures of ISO/IEC 11578:1996 Annex A. user_data_payload_byt shall be a byte containing data having syntax and semantics as specified by the UUID generator. D.2.7 Recovery point SEI message semantics The recovery point SEI message assists a decoder in determining when the decoding process will produce acceptable pictures for display after the decoder initiates random access or after the encoder indicates a broken link in the coded video sequence. When the decoding process is started with the access unit in decoding order associated with the recovery point SEI message, all decoded pictures at or subsequent to the recovery point in output order specified in this SEI message are indicated to be correct or approximately correct in content. Decoded pictures produced by random access at or before the picture associated with the recovery point SEI message need not be correct in content until the indicated recovery point, and the operation of the decoding process starting at the picture associated with the recovery point SEI message may contain references to pictures not available in the decoded picture buffer. In addition, by use of the broken_link_flag, the recovery point SEI message can indicate to the decoder the location of some pictures in the bitstream that can result in serious visual artefacts when displayed, even when the decoding process was begun at the location of a previous IDR access unit in decoding order. NOTE 1 - The broken_link_flag can be used by encoders to indicate the location of a point after which the decoding process for the decoding of some pictures may cause references to pictures that, though a