规定了在计算机程序中需要使用参考号的情况下，对参考站、水线、结构框架、横向舱壁、甲板、舱室（货舱）、舱口、桅杆和货物装卸设备进行编号时使用的约定。尤其适用于传统单壳商船。

Specifies the conventions to be used in numbering reference stations, waterlines, structural frames, transverse bulkheads, decks, compartments (holds, 'tween decks, tanks), hatchways, masts and cargo-handling equipment where reference numbers are required for use in computer programs. Applies in particular to conventional mono-hull merchant ships.