17 CFR § 240.17Ad-20 - Issuer restrictions or prohibitions on ownership by securities intermediaries.
(a) Except as provided in paragraph (c) of this section, no registered transfer agent shall transfer any equity security registered pursuant to section 12 or any equity security that subjects an issuer to reporting under section 15(d) of the Act (15 U.S.C. 78l or 15 U.S.C. 78o(d)) if such security is subject to any restriction or prohibition on transfer to or from a securities intermediary in its capacity as such.
(b) The term securities intermediary means a clearing agency registered under section 17A of the Act (15 U.S.C. 78q-1) or a person, including a bank, broker, or dealer, that in the ordinary course of its business maintains securities accounts for others in its capacity as such.