Is a board of trustees required to use Roberts Rules of Order at meetings?
Roberts Rules of Order are a permissive means of managing a parliamentary society or organization. The rules are persuasive and highly recommended as a basis for holding, managing and performing the duties of a board, organization, or other governing body. That being said, the rules are a private authority and an organization is not required to act in accordance therewith, unless the Board you are on was organized by some other authority which mandates its use (i.e. government agency, larger non-profit, etc) You may want to consult your bylaws or other organization documents (especially the formation documents, if organized by a larger entity) but if there is no mandate upon you, the board could simply choose its own operating procedure.
