  Guest | Specifies guest names and/or their transportation.Provides information regarding the guest name and the guest's mode of transportation. |
| GuestCounts | Specifies guest quantity and guest types. |
| POS | Point of sale
object.Point of Sale (POS) identifies the party or connection channel making the request. |
| SailingInfo | Contains information related to the selected sailing. Typically the selected sailing is one of the sailings returned in the previous sailing availability response.Contains information pertaining to the selected sailing. |
| SearchQualifiers | Used to further qualify the category availability search. |
| SelectedFare | Specifies the fare code and the group code. |
| 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. |
| 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. |