18.—(1) Subject to sub-paragraph (2), certificates or other instruments which confer contractual or property rights (other than rights consisting of an investment of the kind specified by paragraph 21)—
(a)in respect of any investment of the kind specified by any of paragraphs 14 to 17 being an investment held by a person other than the person on whom the rights are conferred by the certificate or instrument; and
(b)the transfer of which may be effected without the consent of that person.
(2) There is excluded from sub-paragraph (1) any instrument which confers rights in respect of two or more investments issued by different persons, or in respect of two or more different investments of the kind specified by paragraph 16 and issued by the same person.