====National Classifications====
GN and HN are subdivided by nations. Two-letter codes are used for nations represented in the current TLD list found online at [https://en.wikipedia.org/wiki/List_of_Internet_topCountry_code_top-level_domainslevel_domain#Country_code_top-level_domains Lists Wikipedia]. (This source is preferred as there are a number of competing agencies and standards.) Nations not represented on this list are assigned two character cutter codes. Note that this results in nations being shelved out of strict alphabetical order (sometimes wildly so, as Switzerland uses CH).
New codes will be assigned as needed, using the Internet's Top Level Domain (TLD) list where possible, and Cutter numbers where not.
===Date Code===
Classification RB is organized by the date of birth of the biographee. When the subject is a couple, the birth date of the senior is used (as Victoria for Victoria & Albert). This avoids the challenges created by monarchs who ruled multiple countries, variations in the spelling of names, and the inadequacy of House names for identification. It has the benefit of shelving contemporaries near one another. Birth dates can be difficult to find, especially in antiquity, but they permit the shelving of living monarchs and heirs, which death dates would not, and nor would coronation dates, which not all achieve. When dates are uncertain, the date given by [https://en.wikipedia.org/wiki/Main_Page Wikipedia] is normally used. Approximate dates are follwed by "c" for circa, as: "1069c".
Dates BC are preceded with those initials, and all dates are padded to four digits. Thus: