IC 3-12-1-4: Ballot void for extrinsic act; erasures

Sec. 4. (a) The whole ballot is void if a voter does any act extrinsic to the ballot, such as enclosing any paper or other article in the folded ballot, with the intent to enable a person to determine that the voter cast the ballot.

(b) An erasure by a voter does not make the whole ballot void unless made with the intent to enable a person to determine who cast the ballot, but it does not register a vote for the elected office, political party office, or public question for which it is made.