(a) An individual who may consent to health care for himself under section 203 of this title may disqualify others from consenting to health care for him.
(b) The disqualification must be in writing, signed by the individual, and designate those disqualified.
(c) A health care provider who knows of a written disqualification may not accept consent to health care from a disqualified individual.
(d) An individual who knows he has been disqualified to consent to health care for another may not act for the other under this chapter.