This is an unofficial version of a Massachusetts General Law.
Section 5-103
(a) A parent or parents of a minor, other than a parent or parents whose parental rights have been terminated or a parent who has signed a voluntary surrender, or a guardian or guardians of a minor or incapacitated person may appoint a temporary agent for a period not exceeding 60 days, and may delegate to such agent any power that the parent or guardian has regarding the care, custody or property of the minor child, ward or incapacitated person, except the power to consent to marriage or adoption of a minor; provided, however, that no parent or guardian shall appoint a temporary agent when a court has ordered that the minor child be placed in the custody of a person other than the parent or guardian.
(b) Any delegation under this section shall be by a writing signed by, or at the direction of, the parent(s) or guardian(s) and attested by at least 2 witnesses 18 years of age or older, neither of whom is the temporary agent together with the written acceptance of the temporary agent.
(c) A parent or guardian may not appoint a temporary agent of a minor if the minor has another living parent whose whereabouts are known and who is willing and able to provide care and custody for the minor unless the nonappointing parent consents to the appointment in writing. A parent may not appoint a temporary agent if the appointing parent's parental rights have been terminated or a parent who has signed a voluntary surrender.
(d) Any delegation under this section may be revoked or amended by the appointing parent(s) or guardian(s) and delivered to all interested persons. The authority of the temporary agent may be limited or altered by the court.