The manufacturer shall ensure that non-conforming product is accepted by concession only if regulatory requirements are met. Records of the identity of the person authorising the concession shall be maintained. Records of the nature of non-conformities and any subsequent actions taken, including concessions obtained, shall be maintained.When nonconforming product is corrected it shall be subject to re-verification to demonstrate conformity to the requirements. When non-conforming product is detected after delivery or use has started, the manufacturer shall take action appropriate to the effects, or potential effects, of the nonconformity. If product needs to be reworked (one or more times), the manufacturer shall document the rework process in a work instruction that has undergone the same authorisation and approval procedure as the original work instruction. Prior to authorisation and approval of the work instruction, a determination of any adverse effect of the rework upon product shall be made and documented.