From SKYbrary Wiki
The process by which a defect, identified on or reported as existing on an aircraft, is assessed to determine what action is going to be required to rectify the defect and, if appropriate, whether the aircraft can continue to fly pending rectification. Usually, this assessment will be made by a Licenced Aircraft Engineer (LAE), holding appropriate certifying approvals, who may decide either that rectification must be accomplished before further flight or that it is allowable under the provisions of the aircraft Minimum Equipment List (MEL) or Configuration Deviation List (CDL). If the latter applies, then an Acceptable Deferred Defect (ADD) will be raised in the Aircraft Technical Log. At locations where no LAE is available and the provisions of the aircraft MEL allow, it may be possible for an aircraft commander to raise an Acceptable Deferred Defect for further assessment by an LAE after a subsequent flight, although since an aircraft commander has no authority to certify an aircraft release to service, such action is taken under the terms of the Captain's Aircraft Acceptance.