Paragraph 15 I1

if the Chair is not present on any occasion, the Vice-Chair shall preside,

if neither the Chair nor the Vice-Chair is present on any occasion, the Commission shall choose another member to preside, and

either the Chair or Vice-Chair may decline to preside on any occasion when the Chair or Vice-Chair, as the case may be, considers it preferable not to do so, in which case sub-paragraph (b) above shall apply.