Section 27E(2) in Conduct of Elections Rules, 1961
(2)The Assistant Returning Officer for the notified class of electors shall at the same time-(a)record on the counterfoil of the ballot paper the electoral roll number of the elector as entered in the marked copy of the electoral roll;(b)mark the name of the elector in the marked copy of the electoral roll to indicate that a ballot paper has been issued to him without, however, recording therein the serial number of the ballot paper issued to that elector;(c)ensure that the elector is not allowed to vote at a polling station.