Checking an upcoming itinerary today, now that My Itineraries is working again.

Saw the ticket, all as expected, Booking Class H as booked, but the fare basis INVOL.

While I'm assuming this is because flight schedules changed and I was auto-rebooked on to new flight numbers/times/equipment, I've never seen it show up like that before. Is this new?

(and perhaps more importantly, does it give me any new rights, like free changes? Actually, I left this one alone because it rebooked in a way that I didn't mind.)