Hum... I see your point... maybe instead of a number (that would be awful!) we could have a link surrounding the "Re:".
Something like this:
<A HREF="http://#126547" target="_new">Re:</A>display of Serial Number before subjects

The number would still be there, but much more intuitive and hidden in the link.

Mateo Byler
<A HREF="http://crucedecaminos.com" target="_new">CruceDeCaminos.com</A>