Our friends at AmericanAirlines have just confirmed for us that the following routing rules apply to BOSEQ ^:

BOS-DFW-LAX-DFW-BOS (roundtrip between BOS-LAX) - ELIGIBLE

BOS-DFW-LAX-DFW-MIA (open jaw with only one BOS-DFW segment) - INELIGIBLE

LAX-DFW-BOS-DFW-SFO (open jaw with two BOS-DFW segments) - ELIGIBLE


So, to summarize, endpoints need not be BOS-DFW, but that segment must be included in both directions. Also, although not stated in the T&C, open jaw itineraries are eligible, again, as long as the BOS-DFW segment is included in both directions.