The new version of the HPD Open Standard is designated as a “dot release” - signified by the use of “2.1” as the name.  In this case, it is the first revision of the current “major release” - Version 2.0.  A dot release differs from a major release in that it contains minor format revisions and optional fields.  It may also contain the resolution of issues previously found, that have been the subject of an erratum/workaround.  In version 2.1 there is one example of this latter use, which is a revision of the Basic Inventory method.