| AreaID | An identifier of an area as defined by a hotel reservation system. |
| BrandCode | A code that identifies the brand or flag of a hotel, often used for independently-owned or franchised properties who are known by a specific brand. |
| BrandName | The name of a brand of hotels (e.g., Courtyard, Hampton Inn). |
| ChainCode | The code that identifies a hotel chain or management group. The hotel chain code is decided between vendors. This attribute is optional if the hotel is an independent property that can be identified by the HotelCode attribute. |
| ChainName | The name of the hotel chain (e.g., Hilton, Marriott, Hyatt, Starwood). |
| HotelCityCode | The IATA city code; for example DCA, ORD. |
| HotelCode | The code that uniquely identifies a single hotel property. The hotel code is decided between vendors. |
| HotelCodeContext | A text field used to communicate the context (or source of - ex Sabre, Galileo, Worldspan, Amadeus) the HotelReferenceGroup codes. |
| HotelName | A text field used to communicate the proper name of the hotel. |
| TTIcode | TTI hotel reference code. |
| 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. |