(1) Subject to subsection (2) and sections 29 to 32, the trustees may under section 16, 17 or 18 appoint a person to act as a nominee or custodian on such terms as to remuneration and other matters as they may determine.

(2) The trustees may not under section 16, 17 or 18 appoint a person to act as a nominee or custodian on any of the terms mentioned in subsection (3) unless it is reasonably necessary for them to do so.

(3) The terms are -

(a) a term permitting the nominee or custodian to appoint a substitute;

(b) a term restricting the liability of the nominee or custodian or his substitute to the trustees or to any beneficiary;

(c) a term permitting the nominee or custodian to act in circumstances capable of giving rise to a conflict of interest.