| NumberOfUnits | The number of rooms for this inventory type code. |
| Duration | The duration datatype represents a combination of year, month, day and time values representing a single duration of time, encoded as a single string. |
| End | The ending value of the time span. |
| InvCode | Code that identifies an inventory item. |
| InvCodeApplication | An enumerated type that identifies whether the InvCode is a single item which can be inventoried or a group of items which can be inventoried. Values are: Does Not Apply, Inventory Code, Inventory Grouping Code. |
| InvType | A value that indicates the type of inventory for which this request is made. If the inventory item is a room, typical values could be double, king, etc. |
| InvTypeCode | Specific system inventory type code. If the inventory item is a room, typical values could be room type code, e.g.: A1K, A1Q etc. Values may use the OpenTravel Code list or a code specific to the property or hotel brand. |
| IsRoom | Simple indicator to detect if inventory is a room. |
| PromotionCode | Promotion code is the identifier used by the host to link directly with a specific named advertising campaign. By including the required code, the client is able to gain access to special offers which may have been created for a specifically targeted group via a CRM system or for a wider advertising campaign using Television or press adverts. |
| PromotionVendorCode | List of the vendor codes associated with a promotion. |
| RatePlanCategory | Hotel systems often group multiple rate plans into a single category. This refers to that category that is specific to the hotel CRS/ PMS and should not be confused with a GDS rate category. |
| RatePlanCode | A string value may be used to request a particular code or an ID if the guest qualifies for a specific rate, such as AARP, AAA, a corporate rate, etc., or to specify a negotiated code as a result of a negotiated rate. |
| RatePlanID | A text field used to indicate a special ID code that is associated with the rate and is essential in the reservation request in order to obtain the rate. Examples are Corporate ID. |
| RatePlanQualifier | The Rate Plan Qualifier is used to control the sort order of RatePlans. Those Rate Plans that are not qualified will appear first, those that are qualified will appear last. |
| RatePlanType | An enumerated type that allows the query to specify a rate category type, and provides major categories for comparison across brands. Refer to OpenTravel Code List Rate Plan Type (RPT). |
| Start | The starting value of the time span. |