(1) References in this Part to a company's constitution include -
(a) any resolution or other decision come to in accordance with the constitution, and
(b) any decision by the members of the company, or a class of members, that is treated by virtue of any enactment or rule of law as equivalent to a decision by the company.
(2) This is in addition to the matters mentioned in section 17 (general provision as to matters contained in company's constitution).