Open Stack

In the contributor guide we recommend the use of tags in the head of
commit
messages: http://docs.openstack.org/contributor-guide/topic-tags.html

It is fine for me to not enforce the use of tags in the head of commit
messages. But I would prefer to use the listed tags when using a tag
in the commit message and to not accept variations of the listed tags.

It is super easy to edit a commit message using the Gerrit web
interface and it would be nice to be a little bit more consistent when
using tags.

Christian.