Regional Trade Agreement. Refer to reciprocal trade agreement between two or more partners, not necessarily belonging to the same region. RTA is an exception to the WTO rule of non-discrimination. WTO members are permitted to enter into an RTA under specific conditions. (WTO, 2023a). WTO members are obliged to notify the RTAs in which they participate. All of the WTO's members have notified participation in one or more RTAs (some members are party to 20 or more). Notifications may also refer to the accession of new parties to an agreement that already exists.