Rick,
personally, I would vote to tag it on the end of the subject line... that way it can be useful to some hacks (especially one in particular that I am working on <img border="0" title="" alt="[Wink]" src="images/icons/wink.gif" /> <img border="0" title="" alt="[Wink]" src="images/icons/wink.gif" /> where I have already added it on in this fashion...)
Right now, I am just adding ~~1234~~ but brackets would work just as well... all I need for my hack is to pull that parent number out of the subject line...
Matt
