There are at least five descending genealogies numbering systems and three ascending genealogies numbering systems. The first system is called the Register System and was developed in 1870 by the New England Historic Genealogical Society. The second system is called the National Genealogical Society Quarterly (NGSQ) System (also known as the Modified Register System) and has been refined by the Nation Genealogical Society. This is the system used in this report.
The third system is called the Henry System. This is a system in which a digit or letter is added for each generation that a person represents, with his numerical value reflecting birth-order within each nuclear family--e.g. 1234 would indicate that the individual was the fourth child of his parent, who was the third child of their parent, who was the second child of the original ancestor. Any children over nine would have a letter, starting with "A" assigned instead of a number, the tenth child would be "A", the eleventh child would be "B", etc. The spouse of a descendant would have an "S" added to the descendant's number. The Henry System lists by generation or by family line. After all the descendants of the first child have been listed, the second child's descendants will be listed.
The fourth and fifth systems list the descendants in the same order as a Descendancy Chart, and are referred to as By Descendants or Family Line--in this, they are similar to the Henry System. The fourth numbering system lists in descendancy order while using the same ID as the Modified Register System. This system is called By Descendants, in Non-Sequential Order, or by generation. The fifth numbering system is called By Descendants, in Sequential Order and lists in descendancy order and uses a sequential numbering system.
Listing By Generation (Modified Register System) is the most common system. The starting individual is listed first as generation one, his children are listed as generation number two, his grand-children are listed as generation number three and so on. Each person is assigned an ID number by the computer in sequential order by generation. When listing By Generation, individuals are listed in numerical order. The superscript numbers reflect the generation. The numbers preceding the names are ID numbers, along with a Roman numeral indicating the birth-order within each nuclear family. A plus (+) to the left of the ID number indicates that the individual will appear again as an adult. If there is a minus (-) or no plus, then all that is known about that individual will appear at that location.