NOTE: Used only in Distribution API.
Reservation represents a reservation made for a certain quantity for a specific offer. As offers in the database mostly are shared between many publishers you never know when a particular offer is sold out. If you schedule to feature an offer let's say in a week and the offer is sold out before the feature day you need to do double work and find another offer as a replacement. Reservations are suppose to guarantee you a specified quantity of the offer vouchers is reserved for you and can not be sold by anyone else.
Reservation functionality is provided free of charge, however it is disabled by default. Only distributors with proven high sales ratio of Adility offers are allowed to use reservation feature.