Iowa Code § 43.92
The date, time, and place of each precinct caucus of a political party shall be published at least twice in at least one newspaper of general circulation in the precinct. The first publication shall be made not more than fifteen days nor less than seven days before the date of the caucus and the second shall be made not more than seven days before and not later than the date of the caucus. Such publication shall also state in substance that each voter affiliated with the specified political party may attend the precinct caucus. Publication in a news item or advertisement in such newspaper shall constitute publication for the purposes of this section. The cost of such publication, if any, shall be paid by the political party.
Iowa Code § 43.92