Hi Phil, The naming conventions page is part of the Dutch Roots project, and yes, anyone can join projects at WikiTree. As far as other projects with naming conventions, several use pages like that to clarify how things are done like the Cymru Welsh project and New Netherland Settlers. Further conventions would be looked at once projects for those regions develop. Who decides this? The Project Leaders, Coordinators, and members, often using discussion on G2G. It just depends on the project's focus and goal. They always aim to use what that person used as a last name during their own lifetime and language, no matter the project, in line with the WikiTree Style guide and rules.