Rec. 2100 is an ITU-R Recommendation that introduces high-dynamic-range television (HDR-TV) by recommending the use of the perceptual quantizer (PQ) or hybrid log-gamma (HLG) transfer functions instead of BT.1886 EOTF and other transfer functions previously recommended for SDR-TV.
Rec. 2100 defines various aspects of HDR-TV such as display resolution (HDTV and UHDTV), frame rate, chroma subsampling, bit depth, color space, and transfer function. It was posted on the International Telecommunication Union (ITU) website on July 4, 2016. Rec. 2100 expands on several aspects of Rec. 2020.