The SeatAvailability transaction set returns data used to construct respective seat maps with fully integrated fees for any identified premium seats. The message also returns multi-media content at the message level with media content references at the individual service level. Implementer-Augmented Structure. An instance of a distribution channel. That is, the set of organizations involved in the development of the current transaction. IATA standard payload attributes. Point of Sale information. SeatAvailability request information.