Just overheard a peculiar conversation between my brother-in-law and an Alaska Airlines agent. He has a companion fare reservation booked for next month ANC-SFO returning SMF-SEA-ANC. He called to change the return date to a day later. The agent said she could not help him because "Multi-City reservations are not permitted for Companion Fares, per the Terms and Conditions", but that she was going to "let him keep it". Never in my years of traveling have I heard this is a breach of Terms and Conditions. As a test, I even tried doing a dummy booking with my Companion code for a similar itinerary, and it worked just fine. Perhaps he just got a bad agent? Or did the agent mean that changes are not allowed for companion fares on a Multi-City reservation?