Replace the first sentence of the first paragraph with the following sentence.
"ISO/IEC 9592 is a multi-part standard that specifies a set of functions for computer graphics programming, the Program-mers's Hierarchical Interactive Graphics System (PHIGS)."
Add the following paragraph before the last paragraph:
"This part of ISO/IEC 9592 is the base part and forms the kernel of PHIGS functionality. ISO/IEC 9592-2 and ISO/IEC 9592-3 are related to archives. Other parts may be defined that presume the functionality of part 1. They may extend part 1 specifications, including, but not limited to, specifying additional output primitives, aspects of output primitives and attributes; extending lists of enumerated types; extending the error lists; etc. Additional parts shall describe their rela-tionship to part 1."