(a) Except as provided in this subpart, subpart A of this part applies to proceedings by the Comptroller to determine whether, pursuant to authority contained in sections 12(i) and 21C of the Exchange Act (15 U.S.C. 78 l(i) and 78u-3), the Comptroller may initiate cease-and-desist proceedings against a national bank for violations of sections 12, 13, 14(a), 14(c), 14(d), 14(f), and 16 of the Exchange Act or regulations or rules issued thereunder (15 U.S.C. 78 l, 78m, 78n(a), 78n(c), 78n(d), 78n(f), and 78p) .(b) All proceedings under this subpart must be commenced, and the notice of charges must be filed, on a public basis, unless otherwise ordered by the Comptroller. Pursuant to § 19.33(a) , any request for a private hearing must be filed within 20 days of service of the notice.