CAL had language if I'm not mistaken to say no RJ/Coex flying between hubs. Let me go look, airlinepilotcentral.com does include the pilot contracts....

look, took 3 minutes:

Continental, Section 1 (Scope) Part 4 B.
The Company will not permit Express Carrier Flying between Company Hubs. If an Express Carrier schedules a pair of successive flights of Express Carrier Flying to be operated either under a single flight number or on a single aircraft, where one flight is scheduled to originate at a Company Hub and the second flight is scheduled to terminate at a second Company Hub, the Company will impose an IATA standard schedules Information Manual Type “A” Traffic Restriction Code on the through flight which will suppress its display.