| POS | The point-of-sale data, contained in the POS element, communicates the information that allows the receiving system to identify the trading partner that is sending the request or the response message.Point of Sale (POS) identifies the party or connection channel making the request. |
| UniqueID | A unique identifier by which to reference the travel itinerary.An identifier used to uniquely reference an object in a system (e.g. an airline reservation reference, customer profile reference, booking confirmation number, or a reference to a previous availability quote). |
| Verification | This is to be used for verification that the record to be returned is the specific record requested.Collection of data used to ensure the correct reservation is canceled or modified (e.g. in the case of a hotel reservation modification, a CustLoyalty/ MembershipID would be verified as part of the reservation that you plan to modify to ensure the correct reservation is being modified). |
| 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. |