23. A decision of the Registrar under regulations 7, 8 or 22 shall take effect –
(a)where no appeal under regulation 24 is brought against the decision within the time limited for the appeal, on the expiration of that time;
(b)where such an appeal is brought and is withdrawn or struck out for want of prosecution, on the withdrawal or striking out of the appeal;
(c)where such an appeal is brought and not withdrawn or struck out as aforesaid, if and when the appeal is dismissed, and not otherwise.