| Description |
| Used for an Alpha String, length 1 to 2 (for letter codes). |
| Type : UpperCaseAlphaLength1to2 |
| Definition |
| The Marketing Carrier Reservation Booking Designator (RBD) to upgrade to. |
| Parents |
| \OTA_AirGetOfferRQ\RequestCriterion\AirItinerary\ItineraryUpgrade\UpgradeSegment
|