Versions of Iowa Code 321.504 - Optional notification on LawServer 2023 Iowa Code 321.504 – Optional notification 2022 Iowa Code 321.504 – Optional notification 2020 Iowa Code 321.504 – Optional notification 2018 Iowa Code 321.504 – Optional notification 2016 Iowa Code 321.504 – Optional notification 2014 Iowa Code 321.504 – Optional notification. 2009 Iowa Code 321.504 – Optional notification