Definicja OTB reservation (IS-R)

Checks available budgets when contracts are created or changed, and provisionally reserves plan budget for the contract or for individual items.

This check is not the same as the OTB check. The criteria for creating a contract are a lot less stict for the OTB reservation. For example, a contract can still be created even if the result of the reservation check is negative. The actual OTB check is performed when a release order for the purchase order is generated.