3.05.16. An advocate who engages in his professional activities within a partnership or joint-stock company shall take reasonable measures to ensure that the partnership or joint-stock company, any person engaging in activities within the partnership or joint-stock company or having an interest therein, a director or an officer refrains from doing one of the following:
(1) acquiring a right of ownership in litigious property when providing professional services to the client;
(2) acting as surety in a matter under the jurisdiction of a court of penal jurisdiction, except where it is justified by his family relationship with the accused;
(3) borrowing from the client the sums of money collected for the client;
(4) collecting interest contrary to section 3.08.07.