If I add a comment on a changeset with this text:
[External link]. : http://example.net/#comment:1
Then I see a link back to the current commit instead of the external site I really wanted to link to. I've left a demo here: https://bitbucket.org/mg/bitbucket-test/commits/5c13c6683ff0 (notice how nice a short link it, I wish I could just copy that directly from my address bar...).