Sometimes when people merge bug fixes/changes from one branch to another they don't include the jira number from the original commit. This makes it exceedingly hard to figure out which branches something has been fixed in from the jira issue or the commit logs.
It's requested that everyone be very careful to include jira numbers on all branch-to-branch merges when the original commit was associated with a jira entry. It's also highly recommended to provide a bit of backup by commenting on the jira entry with the merge revision number as well.
(as per Dave's request in Merge ettiquette)