Family pedigrees require a numbering format that allows the user to easily follow lines down through descendants or back toward the original ancestors. It is best to adopt a system that has been well-established, refined as needed over the years, and is easily understood. "Three basic numbering systems are already in use by experienced genealogists worldwide," according to attorney and certified genealogist Donn Devine. In "How to Number People in Pedigrees and Genealogies," Ancestry Newsletter 4 (1) (January-February 1986), Divine describes and illustrates these widely accepted methods: "(a) the pedigree system; (b) the compiled genealogy system; and (c) the expansible genealogy system, based on the use for which each is most appropriate." Joan Ferris Curran, Numbering Your Genealogy: Sound and Simple Systems (Arlington, Va.: National Genealogical Society, 1992), elaborates on the "two user friendly formats for compilers of descending genealogies"‹the National Genealogical Society Quarterly System (NGSQ, also known as the Modified Register System and sometimes The Record System) and the Register System originated in 1870 by the New England Historic Genealogical Society.