16. No member or associate shall, in contravention of any rules made under this Ordinance, directly or indirectly,-(a) extend or maintain credit, or arrange for the extension or maintenance of credit, to or for any person for the purpose of purchasing or carrying any security; or(b) borrow on any security or land or arrange for the lending of any security carried for the account of a customer; or(c) hypothecate or arrange for the hypothecation of any security carried for the account of any customer.