Iowa Code § 904.510
The superintendent receiving a person committed to any of the institutions shall ask the person to state the person’s religious preference, shall enter the stated preference in a book kept for that purpose, and shall request that the person sign the entry. If the person is a minor and has formed no choice, the preference may be expressed at any later time by the person.
83 Acts, ch 96, §26, 159 CS83, §217A.36 85 Acts, ch 21, §54 CS85, §246.510 C93, §904.510