* change xen-unstable xen/Makefile XEN_EXTRAVERSION
# if main version number has changed (eg 4.7 -> 4.8) rerun ./autogen.sh
* rerun ./autogen.sh to update version number in configure
-# - XEN_EXTRAVERSION should be `.0-rc$(XEN_VENDORVERSION)'
+# - XEN_EXTRAVERSION should be as follows
+# `.0-rc$(XEN_VENDORVERSION)' during freeze, first rc onwards (including staging, before branching)
+# `-unstable$(XEN_VENDORVERSION)' unstable aka unfrozen staging (or unstable branch, after branching)
+# `.0$(XEN_VENDORVERSION)' actual release of Xen X.Y.0 (aka first actual release of Xen X.Y)
+# `.Z$(XEN_VENDORVERSION)' actual release of Xen X.Y.Z (stable point realase)
#
# - turn off debug on stable branches, if not already done
# - tools/Rules.mk