A similar system is also heavily used in the construction world in their "Work Breakdown Structure" - a borrowing on how they document airplane parts that are part of an assembly, that are part of a module, that part of a structure.

http://en.wikipedia.org/wiki/Work_breakdown_structure

Thanks for the name! We do this internally to store various levels of product data in a single mongo collection (e.g., style, variant).

Thanks! I wanted to know what it is called.