 FareBasisCode | Up to 9 requested fare basis codes. |
| FareQuoteCriteria | Specific criteria for qualifying fare options. |
| PassengerCategory | Passenger type, category and quantity information, including occupation, passenger qualifying codes, rate qualifiers and disability requirements. |
 POS | Point of Sale Identification for the transaction initiator that includes the identification information of the party that has made the reservation request and optional information, such as an agency number assigned by IATA, ARC, ESRP or TID.Point of Sale (POS) identifies the party or connection channel making the request. |
| RateQualifier | Rate qualifying information such as travel purpose, promotion codes and rate category that may affect the fare.Defines rate qualifying information such as travel purpose, promotion codes and discount types that may affect the fare. |
| TPA_Extensions | A placeholder in the schema to allow for additional elements and attributes to be included per Trading Partner Agreement (TPA).Allows extensions to be added to the OpenTravel specification per trading partner agreement. |
| TravelerPref | Traveler preferences including accommodation and class codes. |
| AltLangID | The alternate language for a customer or message encoded as ISO 639-3. |
| CorrelationID | Allows end-to-end correlation of log messages with the corresponding Web service message throughout the processing of the Web service message. |
| EchoToken | A reference for additional message identification, assigned by the requesting host system. |
| PrimaryLangID | The primary language preference for the message encoded as ISO 639-3. |
| RetransmissionIndicator | When true, indicates the message is being re-sent after a failure. |
| SequenceNmbr | The sequence number of the transaction assigned by the sending system for ordered message processing or message resynchronization. |
| Target | Test or Production target system indicator. |
| TargetName | The name of the Test or Production system. |
| TimeStamp | ISO 8601 encoded timestamp indicating the creation date and time of the message. |
| TransactionIdentifier | Unique identifier to relate all messages within a transaction (e.g. this would be sent in all request and response messages that are part of an on-going transaction). |
| TransactionStatusCode | This indicates where this message falls within a sequence of messages. |
| Version | The OpenTravel message version indicated by a decimal value. |