Iowa Code § 633A.4207: Directory powers.

1. While a trust is revocable, the trustee may follow a written direction of the settlor that is contrary to the terms of the trust.

2. In addition to any powers granted to a trustee, the terms of the trust may confer powers upon trust directors and trust protectors as set forth in sections 633A.4801 through 633A.4810. A person’s status as a trust director or trust protector under Iowa law shall be determined on the basis of the powers granted and not on the title given to such person in the trust instrument.