In a manufacturing environment, a request for waiver (RFW) is a request for authorization to accept an item which, during manufacture or after inspection, is found to depart from specified requirements, but nevertheless is considered suitable for use as is or after rework by an approved method.
This is significant in the process of developing a pre-defined manufacturing procedure. A Request for Deviation, in contrast, happens before production of the item.
References
Request for waiver Wikipedia(Text) CC BY-SA