This standard covers those devices whose primary function is locking@ and excludes those devices which have integral locking features incorporated into the item being locked. The practices cover the types or locking devices described in the following sections: Section I Lock Wire Section II Key Washers Section III Cotter Pins Special applications involving conditions not covered by the basic principles described here in shall be shown on the drawing@ and where contradiction occurs between a drawing and this instruction@ the drawing shall prevail. PURPOSE: To establish the requirements of good practices for locking various fasteners and other parts which may require locking in critical applications such as aerospace propulsion systems.