<https://groups.google.com/a/groups.riscv.org/d/msg/isa-dev/x-uFZDXiOxY/_ISBs1enCgAJ>.
Now updated with its own spec [[isamux_isans]].
-## Executive Summary
+[[!toc ]]
+
+## Executive Summary (old, still relevant for compilers)
A non-invasive backwards-compatible change to make mvendorid and marchid
being read-only to be a formal declaration of an architecture having no