§ 1710. Will or deed containing appointment to be proved

A person shall not exercise within the state any power or authority as
guardian of the person or property of an infant by virtue of the
appointment by the will of an infant's parent, being a domiciliary and
dying after this act takes effect, unless the will has been duly
admitted to probate and recorded in the proper court and letters of
guardianship have been issued thereon; or by virtue of an appointment
contained in a deed of the infant's parent, being a domiciliary,
executed after this act takes effect, unless the deed has been
acknowledged so as to entitle it to be recorded and has been recorded in
the office for recording deeds in the county of domicile of the person
making the appointment at the time of execution thereof.