Software Foundation), was to quite simply make the mvendorid and marchid
CSRs have WARL (writeable) characteristics. For instances where mvendorid
and marchid are readable, that would be taken to be a Standards-mandatory
-"declaration" that the architecture has *no* Custom Extensions.
+"declaration" that the architecture has *no* Custom Extensions (and that
+it conforms precisely to one and only one specific variant of the
+RISC-V Specification).
This incredibly simple non-invasive idea has some unique and distinct
advantages over other proposals: