The actual upgrade process will be done by a new command ``upgrade`` to
``gnt-cluster``. If called with the option ``--to`` which take precisely
one argument, the version to
-upgrade (or downgrade) to, given as full string with major, minor, suffix,
+upgrade (or downgrade) to, given as full string with major, minor, revision,
and suffix. To be compatible with current configuration upgrade and downgrade
procedures, the new version must be of the same major version and
either an equal or higher minor version, or precisely the previous