>> * Another committer review the request. This reviewer checks if this
>> =A0 commit is good enough and backport it to the older branch.
>
> Do you mean the word "backport" as committing?
> If so, who changes patchlevel?
> The committer? You?

btw, I have an additional proposal. I think every backport commits
should have got a review _before_ backport commit and the commit
messages should have Reviewed-by tag (ie. who reviewed the patch).