Branches are mutable, tags aren’t. You can add a commit to `v4.11-rc7-87` anytime. Now your branch has grown past the merge commit. Confusion ensues. Compared

Branches are mutable, tags aren’t. You can add a commit to `v4.11-rc7-87` anytime. Now your branch has grown past the merge commit. Confusion ensues. Compared to a tag, you’d have to deliberately go out of your way to move a tag (`git tag -f`). Generally, you should be able to trust your team members not to move a tag.