rules of an exchange
(27) The term “rules of an exchange”, “rules of an association”, or “rules of a clearing agency” means the constitution, articles of incorporation, bylaws, and rules, or instruments corresponding to the foregoing, of an exchange, association of brokers and dealers, or clearing agency, respectively, and such of the stated policies, practices, and interpretations of such exchange, association, or clearing agency as the Commission, by rule, may determine to be necessary or appropriate in the public interest or for the protection of investors to be deemed to be rules of such exchange, association, or clearing agency.