Jim is correct in saying the Customer defines the requirements. An example from one of our Customers reads:
1 Level One Controlled Shipping (CS1) - Controlled Shipping is a formal demand by Customer for a supplier to put in place an additional inspection process to sort for nonconforming material, while implementing root-cause analysis and corrective actions. The Controlled Shipping process is in addition to normal controls. The data obtained from the Controlled Shipping inspection process is critical as both a measure of the effectiveness of the containment process and the corrective actions taken to eliminate the initial nonconformance.
2 Level Two Controlled Shipping - Includes the same processes as Level 1 Controlled Shipping with an additional inspection process that is completed by a third party. Customer and the supplier mutually agree upon the third party company and location. The third party company must be minimum certified to ISO 9001:2000.
Hope this helps