It wouldn't be in the Conditions of Carriage, but in the fare rules for your specific fare. If you still have the full fare basis, there are folks here who have ways of finding the fare rules.
Cheers.
I guess I'll just have to start downloading these in the future. For this one, I don't even remember the code, so I'll just ask AA. If I don't get a refund, I'm fine with original routing credit, in any case.
Edit: I just found my reservation confirmation, and these two flights were on an "N" code. I don't know if that helps, or if the fare regs are consistent for N codes, anyway.