Originally Posted by
sethb
RUCs work on X. The problem might be a "broken fare": each segment was a separate fare rather than a through fare. That makes it unclear whether a single RUC should work for both flights.
Officially broken fares require multiple RUCs, but many agents probably don't know this and others might let it pass so that a single RUC covers all segments in the same direction (but not a RT, even if it's a same day MR). YMMV.