Originally Posted by
dc10forlife
If you take the credit (after a price drop) and need to change again, simply cancel the ticket. You will get an additional credit. Then book the new flights you want and apply both credits.
I'm not so sure that works. Certainly the corporate travel agent couldn't figure this out (although admittedly they're not the best).
AA.com's page on
travel credits does explicitly say that "You may not combine Trip Credit with the value of an existing ticket to pay for a new ticket." but it's a little confusing as to what exactly Trip Credit vs. Flight Credit is.