(5)Cancellation by record-keeper. - It shall be the duty of the record-keeper of the Court or office to-(a)examine every document which comes into his custody in order to ascertain firstly whether all stamps and labels have been cancelled as required by the above rules, and secondly, whether the value of label or labels, if any, which it bears, corresponds with their values as noted in the receiving court or office, and(b)cancel each label by a circular date stamp bearing date, month and year and the name of the Court or office concerned.Black ink shall be used with this stamp.