| BasePeriodRPHs | Use with an 'AddOn' DurationPeriod to point to the 'Base' DurationPeriod(s) which it extends. |
| Category | Identifies the unit on which on Extra is charged, e.g. per person, room, adult etc. |
| DurationPeriod | Defines the period for which a charge applies, e.g. P1D = per day, P1N = per night, P7D = per week etc. If this attribute is not present, the period is assumed to be the duration of the booking. |
| GuidePriceIndicator | When 'true', the accompanying price(s) are guidelines; full pricing will be returned when the Extra is selected in a Quick Cost message. When 'false', an accurate costing can be calculated from the price(s) given. When this attribute is absent, accurate prices will be assumed. |
| MaximumPeriod | The maximum period for which the associated service is bookable. |
| PriceBasis | An enumerated type that defines how a service is priced. Values: Per stay, Per person, Per night, Per person per night, Per use. An enumerated type that defines how a service is priced. Values: Per stay, Per person, Per night, Per person per night, Per use. |
| RPH | (Reference Place Holder) - an index code to identify an instance in a collection of like items.. For example, used to assign individual passengers or clients to particular itinerary items. |
| Type | Indicates whether the DurationPeriod is a 'Base' (i.e.. a charge for one of a tier of durations like 3days, 7days etc.) or 'AddOn' (i.e. for periods extending a base period like extra day, extra week etc.) |
| 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. |
| Start | The starting value of the time span. |
Price