A series of snapshots of well-supported modules have been compiled and published as W3C Recommendations: 5.0 (2014); 5.1 (2016); 5.2 (2017). The latest W3C Recommendation is a result of a May 2019 agreement between W3C and the WHATWG regarding the development of a single version of the HTML specification.Reference : https://www.loc.gov/preservation/digital/formats/fdd/fdd000481.shtml