A Power of Attorney is a written document in which a competent adult (a.k.a. the "principal") appoints another competent adult (a.k.a. the "attorney-in-fact" or "agent") to act on the principal's behalf. In general, an attorney-in-fact may perform any legal function or task which the principal has a right to do so long as the power to do so is specified in the document. The powers may be very broad or very narrow; they may be effective immediately or upon incapacity. The term "durable" means that the power remains in force for the lifetime of the principal, even during incapacity of the principal.