Ticket description diff in email notifications is not useful (BB-9026)
I often get emails trying to show a diff between the old and the updated description of a ticket but that often just ends in "oh, all of the old stuff has been removed and the new stuff added" even though it looks like nothing changed at all. (Examples: https://bitbucket.org/birkenfeld/sphinx/issue/1230 https://bitbucket.org/birkenfeld/sphinx/issue/1216 https://bitbucket.org/birkenfeld/sphinx/issue/1218/) It might be that markup changed subtly, but that's hardly recognizable in the email notifications.
Also, for code blocks it strips all whitespace which ends up rendering the diff unreadable as well. (Example: https://bitbucket.org/birkenfeld/sphinx/issue/1170/)