The General Directorate for Defense Investments and Armaments (GDDIA) Directorate Offsets & Quality Assurance in the Codification Division, operates the Greek National Codification Bureau, which is responsible for the NATO Codification System in operation. Among the activities of the department is to coordinate activities of Initial Service Coding Materials (Codification) for coding of materials. In detail, the activities of the National Codification Bureau, mission, history, organization, coding instructions, and publications, information concerning at NATO codification materials are given here (in NATO Materials Codification).