2 Grounds for invalidity or nullity that relate to cantonal procedures (official voting envelope, validation stamp, etc.) are reserved.
3 In the case of electronic voting pilot schemes28, the legislation of each canton conducting such a scheme shall determine the requirements according to which votes are validly cast and the grounds for invalidity.29
28 Term in accordance with No II 4 of the Federal Act of 20 March 2008 on the Formal Revision of Federal Legislation, with effect from 1 Aug. 2008 (AS 20083437; BBl 2007 6121). This amendment has been made throughout the text.