Provides a file format suitable for the storage and retrieval of PHIGS structure and structure definitions. The file format consists of a set of elements that represent structure elements in a way that is compatible between systems of different architectures and devices of differing capabilities and design. It is identical with and has been reproduced from ISO/IEC 9592-2:1989, Information processing systems - Computer graphics - Programmer's Hierarchical Interactive Graphics System (PHIGS), Part 2: Archive file format.