Mr. Bangor and Aroostook, a Coupon Station was one that could issue interline tickets. "Once upon a time", those tickets would be a long fanfold of coupons; one such for each road over which the passenger's journey would involve. For example, as a kid, say about '53, I saw first hand a Round Trip ticket from Stamford CT to Ormond Beach FL for travel my Mother and Grandmother were taking together. That ticket was some eleven coupons and stretched for about 18". It read NH-Stamford-NY Penn Station-PRR-Wash-RF&P-Richmond-ACL-Jax-FEC-Ormond Beach. All plus a passenger receipt. Additionally two Pullman tickets for the Compartment in both directions.
Here's a "shorty" one of such issued by the New Haven:
This coupon ticket was good from Stamford to any station on any of the four roads interlining with the PRR at Wash. Also, be sure to note how the ticket states via Hell Gate Bridge, for there was a "bridge toll" (about $1 as I recall) applicable to any interline ticket so routed. However, you could originate on the New Haven; Penn to "wherever", without paying that "toll".