Register Numbering System

Example of a descendant genealogy report using the register system from the New England Historic and Genealogical Register, Vol LX, 1906, pp 142–143
NEHGS / Internet Archive

Based on the numbering system developed by the New England Historical and Genealogical Society in 1870, the register system is one of the two main systems in use today for numbering descendant reports—genealogy reports that outline the descendants from a particular ancestor. The register system is used for published family genealogies in the "New England Historical and Genealogical Register," the flagship journal of the New England Historical and Genealogical Society, thus the name "register system." The register numbering method was also the primary numbering system used for family histories published in the late 1800s and early 1900s.

Pros and Cons of the Register System

The register system was developed as a method of outlining all known descendants of a given individual, making it easier to track a line through multiple generations. The register numbering system is best used for final publication, not research in progress, as it is requires extensive renumbering any time additions or corrections are made. Another drawback of the register numbering system is that only blood-line descendants are assigned numbers (spouses do not receive a number).

How to Read a Register Report

The key to reading a register report is to understand its numbering system. The progenitor, or primary individual, is given the number 1. Each of his children is then numbered in sequential order by birth with lower-case Roman numerals (i, ii, iii, iv, etc.). If the birth order is not known, the children are generally listed in the most-likely order of birth.

Children with known lines of descent included later in the report are also given an Arabic number (1, 2, 3, 4, etc.).

Except for the primary individual, every person assigned an Arabic number in the register numbering system appears first as a child. The number they are assigned as a child indicates his/her position in the adult descent line.

If only a roman numeral appears next to a child, then there are no descendants included in the report for that individual, and it is the last time that child will appear in the register report.

Superscript numbers listed immediately following a person's name are generally used in the register system to indicates the number of generations that person is removed from the progenitor (number 1).

What Does the Register Numbering System Look Like?

To look at it visually, here is the layout of a simplified register report:

Descendants of George Herbert Walker Bush

1. George Herbert Walker Bush, 41st President of the United
States, was born 12 June 1924 in Milton, Massachusetts. He
married Barbara Pierce 06 January 1945 in Rye, New York,
daughter of Marvin Pierce and Pauline Robinson. She was born
08 June 1925 in Rye, New York.

Children of George Bush and Barbara Pierce:

    2.   i George Walker Bush, b. 06 July 1946, New Haven,
           Connecticut
        ii John (Jeb) Ellis Bush, b. 11 February 1953, Midland,
           Midland County, Texas
       iii Neil Mallon Bush
        iv Marvin Bush
         v Robin Bush
        vi Dorothy Bush

Second Generation:

2. George Walker Bush (George Herbert Walker1), 43rd 
President of the United States, was born 06 July 1946 in New Haven, 
Connecticut. He married Laura Welch in 1977 in Midland, Texas. 
Children of George Walker Bush and Laura Welch: 

         i Barbara Bush, b. 1981 
        ii Jenna Bush, b. 1981

In this example, the only descendant of George Bush and Barbara Pierce who has descendants discussed later in the report is George Walker Bush. Thus, he is the only one assigned an Arabic number (in this case, 2). After their initial appearance as a child, numbered individuals will appear in the report in numerical order, which helps you to track a particular family line both backwards and forwards. A modified version of this numbering system, known as the NGSQ System, assigns an Arabic number to every child, regardless of whether additional information about that child's descendants appears later in the report.