Each row says what is behind its code before you follow it. Article — the entry is written and has its own page. Brief — no page of its own yet; the link leads to whatever holds it. Register row — the code exists and the entry is not written. The register is wider than the library of written entries, and always will be; this line is here so the interface does not pass one off as the other.
Counts and order are read from register v60.25 at build time. The right column carries the year a house was founded and the people in Part IX who anchor it, where the Library holds them — read from the Library’s own entry lines, so where an entry flags its date as uncertain no year is shown here and that entry’s page remains the authority. The opening above is editorial; the figures beside it are counted from the rows at build time.