Artikel 15

1. The existence, extent, modification and extinction of powers of representation granted by an adult, either under an agreement or by a unilateral act, to be exercised when such adult is not in a position to protect his or her interests, are governed by the law of the State of the adult’s habitual residence at the time of the agreement or act, unless one of the laws mentioned in paragraph 2 has been designated expressly in writing.
2. The States whose laws may be designated are -
a) a State of which the adult is a national;
b) the State of a former habitual residence of the adult;
c) a State in which property of the adult is located, with respect to that property.
3. The manner of exercise of such powers of representation is governed by the law of the State in which they are exercised.