prevFrameNumOffset may be set equal to any integer multiple of MaxFrameNum in the range of 0 to 231 - 1, inclusive, and prevFrameNum may be set equal to any value in the range of 0 to MaxFrameNum 1, inclusive. For example, the value 0 may be assigned to all of the variables prevPicOrderCntMsb, prevPicOrderCntLsb, prevFrameNumOffset, and prevFrameNum. When exact_match_flag is equal to 1, it is a requirement of bitstream conformance that the values of the samples in the decoded pictures at or subsequent to the recovery point in output order shall be independent of the values that a decoder assigns to the variables prevPicOrderCntMsb, prevPicOrderCntLsb, prevFrameNumOffset, and prevFrameNum used in clause 8.2.1 for deriving the picture order count variables for the initialization of the decoding process at the picture associated with the recovery point SEI message, and of the values that are assigned to the TopFieldOrderCnt and BottomFieldOrderCnt variables of the reference pictures that are not available due to the random access operation. broken_link_flag indicates the presence or absence of a broken link in the NAL unit stream at the location of the recovery point SEI message and is assigned further semantics as follows: If broken_link_flag is equal to 1, pictures produced by starting the decoding process at the location of a previous IDR access unit may contain undesirable visual artefacts to the extent that decoded pictures at and subsequent to the access unit associated with the recovery point SEI message in decoding order should not be displayed until the specified recovery point in output order. Otherwise (broken_link_flag is equal to 0), no indication is given regarding any potential presence of visual artefacts. Regardless of the value of the broken_link_flag, pictures subsequent to the specified recovery point in output order are specified to be correct or approximately correct in content. NOTE 5 - When a sub-sequence information SEI message is present in conjunction with a recovery point SEI message in w