 or 88 and level idc not equal to 11 in bitstreams conforming to this Recommendation | International Standard. Decoders shall ignore the value of constraint_set3_flag when profile_idc is equal to 66, 77, or 88 and level idc is not equal to 11. constraint_set4_flag is specified as follows: Rec. ITU-T H.264 (01/2012) If profile_idc is equal to 77, 88, or 100, constraint_set4_flag equal to 1 indicates that the value of frame_mbs_only_flag is equal to 1. constraint_set4_flag equal to 0 indicates that the value of frame_mbs_only_flag may or may not be equal to 1. Otherwise, if profile_ido is equal to 118 or 128, constraint_set4_flag equal to 1 indicates that the coded video sequence obeys all constraints specified in clause H.10.1.1. constraint_set4_flag equal to 0 indicates that the coded video sequence may or may not obey the constraints specified in clause H.10.1.1. Otherwise (profile_id is not equal to 77, 88, 100, 118, or 128), the value of 1 for constraint set4 flag is reserved for future use by ITU-TI ISO/IEC. constraint_set4_flag shall be equal to 0 for coded video sequences with profile_idc not equal to 77, 88, 100, 118, or 128 in bitstreams conforming to this Recommendation International Standard. Decoders shall ignore the value of constraint_set4_flag when profile_idc is not equal to 77, 88, 100, 118, or 128. constraint_set5_fl is specified as follows: If profile_ idc is equal to 77, 88, or 100, constraint_set5_flag equal to 1 indicates that B slice types are not present in the coded video sequence. constraint_set5_flag equal to 0 indicates that B slice types may or may not be present in the coded video sequence. Otherwise, if profile_idc is equal to 118, constraint_set5_flag equal to 1 indicates that the coded video sequence obeys all constraints specified in clause H.10.1.2 and constraint_set5_flag equal to 0 indicates that the coded video sequence may or may not obey all constraints specified in clause H.10.1.2. Otherwise (profile_ idc is not equal to 77, 88, 100, or 118), the value of 1 for constraint_s