title: What is the process for submitting a github pull request for a modification to an earlier tagged version of a repository?
body: <p>I have created a patch, in a fork, for an older version of a project hosted on github.  Having checked out the tag for the version I'm fixing, committing my change and creating a new tag, I'm not sure how to proceed.  Pull request seem to only compare branches.  </p>
  
  <p>Is there a process for this?</p>