 <p>Note that from April 2013 ("<a href="https://github.com/blog/1451-branch-and-tag-labels-for-commit-pages" rel="nofollow noreferrer">Branch and Tag Labels For Commit Pages</a>"):</p> <ul> <li>Any commit can mention the branch it is part of:</li> </ul> <p><img src="https://i.stack.imgur.com/mb9HQ.png" alt="branch part of commit"></p> <blockquote> <p>If the commit is not on the default branch, the indicator will show the branches which contain the commit. <strong>If the commit is part of an unmerged pull request, a link will be shown</strong>.</p> </blockquote> <p><img src="https://i.stack.imgur.com/GAN5L.png" alt="Link to pull request"></p> <p>That means referencing a commit from the issue will allow the user to see the branch (by looking at the commit), and even to see a link back to the issue (still by looking at the commit).</p>