21.—(1) The register of electors shall for the purposes of this Part be conclusive on the following questions–
(a)whether or not a person registered in it was on the qualifying date resident at the address shown; and
(b)whether or not that address is in any local government area or any particular part of a local government area.
(2) Any entry in the register of local government electors, if it gives a date as that on which the person named will attain voting age, shall for any purpose of this Part relating to him as elector be conclusive that until the date given in the entry he is not of voting age nor entitled to be treated as an elector except for the purposes of a Scottish parliamentary election at which the date fixed for the poll is that or a later date.
(3) A person registered as a local government elector, or entered in the list of proxies, shall not be excluded from voting at a Scottish parliamentary election on any of the grounds set out in paragraph (4) below; but this shall not prevent the rejection of the vote on a scrutiny, or affect his liability to any penalty for voting.
(4) The grounds referred to in paragraph (3) above are–
(a)that he is not of voting age;
(b)that he is not, or, on the qualifying date or the date of his appointment (as the case may be); was not–
(i)a Commonwealth citizen;
(ii)a citizen of the Republic of Ireland,
(iii)a relevant citizen of the Union;
(c)that he is, or, on the qualifying date or the date of his appointment (as the case may be), was, otherwise subject to any other legal incapacity to vote.