This revised Rec. ITU-T H.273 adds the specification of code point identifiers for YCgCo-R colour representation with equal luma and chroma bit depths and for the colour representation specified in SMPTE ST 2128. The new code points for YCgCo-R are referred to as YCgCo-Re and YCgCo-Ro, where the number of bits added to a source RGB bit depth is 2 (i.e., even) and 1 (i.e., odd), respectively. SMPTE ST 2128 specifies a colour representation referred to as IPT-PQ-C2 This Recommendation was developed jointly with ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information, and Rec. ITU-T H.273 is maintained as technically aligned twin text with ISO/IEC 23091-2. The changes specified in this version correspond to the technical content of a not-yet-published future (third) edition of ISO/IEC 23091-2.