(1) The ballot sheet is invalid, if:

1. the vote was cast by using any other than the official ballot sheet or a ballot sheet from a different round of voting, or
2. the ballot sheet is partly torn in a way that it is no longer evident which candidate the voter wished to select (ballot sheet pursuant Section 11 paragraph 2), which candidate he wished to enter (ballot sheet pursuant to Section 11, paragraph 3) or whether he had answered the question according to Section 11, paragraph 4, with „yes“ or „no“, or
3. no candidate is checked (ballot sheet pursuant to Section 11, paragraph 2) or entered (ballot sheet pursuant to Section 11, paragraph 3) or no markings whatsoever appear on it (ballot sheet pursuant to Section 11, paragraph 4), or
4. two or more candidates are checked (ballot sheet pursuant to Section 11 paragraph 2) or entered (ballot sheet pursuant to Section 11 paragraph 3), or the question according to Section 11, paragraph 4, has been answered by „yes“ as well a by „no“, or
5. a candidate has been entered whose name has not been published by the Federal Election Commission pursuant to Section 19, paragraph 1 (ballot sheet pursuant to Section 11, paragraph 3), or 
6. the signs or other markings (ballot sheet pursuant to Section 11, paragraph 2) or entries (ballot sheet pursuant to Section 11, paragraph 3) appearing on the ballot sheet do not clearly indicate which candidate the voter had wished to select, or whether he had wished to answer the question under Section 11 paragraph 4 with „yes“ or „no“.

(2) If a voting envelope contains several ballot sheets not deemed invalid otherwise, these are counted as one invalid vote, if different candidates are indicated on them. Empty voting envelopes are counted as invalid votes.

(3) Words, notes or signs appearing on official ballot sheets other than those indicating the candidate selected (ballot sheet pursuant to Section 11, paragraph 2), naming the candidate selected (ballot sheet pursuant to Section 11, paragraph 3) or checking the word "yes" or "no" (ballot sheet pursuant to Section 11, paragraph 4), shall not impair the validity of an official ballot sheet, unless they cause invalidity for any of the above mentioned reasons. Enclosures of any kind contained in the voting envelope shall not affect the validity of an official ballot sheet.