 BaggageInfo | Specifies baggage information for each passenger checking in or the head of a baggage pool. |
| DocumentAndPrintInfo | Specifies print information that should be used by the receiver to print various Check-in documents. |
| FlightInfo | Identifies the flight segment(s) to be checked in. The carrier will determine how many segments are eligible for continued flight check in. This information applies to all passengers. |
| MessageFunction | Specifies the primary function(s) of a particular Check-in message. |
| Offer | Merchandising offers associated with the fare or traveler.A choice between specifying summary, priced or traveler purchased ancillary offers. |
| PassengerFlightInfo | Captures information for a specific passenger travelling on a specific flight or segment. |
 PassengerInfo | Specifies information related to the passenger checking in. |
| PaymentInfo | Captures payment information for services or fees not covered in the fare. |
| POS | Point of sale object.Point of Sale (POS) identifies the party or connection channel making the request. |
| 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. |