Rainbow membership applications, called petitions, are readily available. Any active Rainbow girl, Mason, Eastern Star, Amaranth, or majority member can obtain a petition for an interested girl. Advisory Board Members can assist in completing the form. A prospective candidate must be sponsored by another girl who is a active member in good standing, and at least one adult who must be a member in good standing of either the Masonic Lodge, Order of the Eastern Star, White Shrine, or Order of the Amaranth (again, an Advisory Board member can help in this measure).