MIL-STD-1808, DEPARTMENT OF DEFENSE INTERFACE STANDARD: SYSTEM SUBSYSTEM SUB-SUBSYSTEM NUMBERING (10 OCT 1990) [SUPERSEDES DOD-STD-863]., This standard sets forth requirements for the system, subsystem, and sub-subsystem numbering requirements for engineering drawings, technical manual, and other acquisition and logistics support requirements for aircraft, missile and space systems, engines, and ground communication-electronic equipment. Additionally, it may be used for supportability analysis, configuration management, maintenance data collection, or where ever a consistent maintainability related reference numbering requirement exists across a weapon system.