| BestAvailableRateCandidate | Use to request Best Available Rate. |
| DateRange | A date or range of dates for the request criteria. |
| DeltaCandidate | Use to request Delta. |
| DestinationSystemsCode | A collection of destination system codes. These are systems for which this request is targeted.A collection of DestinationSystemCode. |
| HotelRef | Indicates the detail of hotel reference information. |
| HurdleRateCandidate | Use to request Hurdle Rates. |
| LengthsOfStayCandidates | Collection of Length of Stay elements. These LOS elements indicate what LOS restrictions are to be included in the response. |
| Offers | Collection of requested offers. |
| RatePlanCandidates | Collection of requested rate plans. |
| RebatePrograms | Used to request rebate programs the hotel participates in. |
| RestrictionStatusCandidates | A collection of Restriction Status values. |
| RoomTypeCandidates | Collection of room stay candidates. |
| 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. |