20.—(1) A CRO may, if the CRO thinks fit, at any time before the publication under rule 18 of the statement of persons nominated as candidates for return as a constituency member, correct minor errors in the nomination paper.
(2) A RRO may, if the RRO thinks fit, at any time before the publication under rule 19 of the statement of persons and parties nominated for return as regional members, correct minor errors in the nomination paper.
(3) Errors which may be corrected include obvious errors of spelling in relation to the details of a candidate or a party.
(4) Anything done by a CRO or RRO in pursuance of this rule must not be questioned in any proceedings other than proceedings on an election petition.
(5) A CRO or RRO must have regard to any guidance issued by the Electoral Commission for the purposes of this rule.