Iowa Code § 52.31: Procedure where votes cast on optical scan ballots.

Preparations for voting and voting at any election in a precinct where votes are to be received on optical scan ballots shall be in accordance with the provisions of chapter 49 governing voting upon conventional paper ballots with the following exceptions:

1. Before entering the voting booth each voter shall be cautioned to mark the ballot only with a ballot marking device provided in the booth or by the precinct election officials.

2. In each precinct where portable automatic tabulating equipment is used, the voter may personally insert the ballot into the tabulating device.