A Part III authority may only be varied under the following provisions:
(a) section 41CK;
(b) a provision of the authority (if any) that provides for the authority to be varied.
Note: Interests in a Part III authority may be assigned under section 41B (which applies in relation to a rehabilitation authority in a corresponding way to the way in which it applies in relation to an authority under section 41: see section 41CG).