Iowa Code § 372.3: Home rule charter.

If a petition for appointment of a home rule charter commission is filed with the city clerk not more than ten days after the council has published the first notice announcing the date of the special election on adoption of another form of government, the special election shall not be held until the charter proposed by the home rule charter commission is filed. Both forms must be published as provided in section 372.9 and submitted to the voters at the special election.