Section 20 of the Principal Act is amended as follows:

(a) by omitting from subsection (1) "Board" three times occurring and substituting "Tribunal" ;

(b) by omitting from subsection (2) "Board" and substituting "Tribunal" ;

(c) by omitting from subsection (3) "Board" and substituting "Tribunal" ;

(d) by omitting from subsection (4) "Board" and substituting "Tribunal" ;

(e) by omitting from subsection (5) "Board" and substituting "Tribunal" .