In determining the consequences of events that delay performance, the U.S. Court of Federal Claims and the Postal Service Board of Contract Appeals have applied general risk-allocation principles. These have been supplemented by contract clauses under which the time and cost effect of delays are dealt with separately. Clause B-19: Excusable Delays deals with the types of events that protect the supplier from sanctions for late performance. Other clauses, such as Clause B-16: Suspensions and Delays, cover the recovery of costs associated with delays. The supplier bears the risk of schedule and cost effects for delays it causes or for delays within its control. Generally, the supplier is excused from nonperformance due to delays caused by factors for which neither the supplier nor the Postal Service is responsible. However, the supplier must bear the cost impact of such delays. The Postal Service is responsible for the schedule and cost effects of delays it causes, delays that are under its control, or delays for which it has agreed to compensate the supplier. Clause B-15: Notice of Delay requires the supplier to notify the contracting officer of problems that might delay performance. Paragraph c of Clause 4-1: General Terms and Conditions incorporate by reference each of these clauses.