Article 15

1. In exercising their jurisdiction under the provisions of Chapter II, the authorities of the Contracting States shall apply their own law.

2. However, in so far as the protection of the person or the property of the child requires, they may exceptionally apply or take into consideration the law of another State with which the situation has a substantial connection.

3. If the child's habitual residence changes to another Contracting State, the law of that other State governs, from the time of the change, the conditions of application of the measures taken in the State of the former habitual residence.

Article 16

1. The attribution or extinction of parental responsibility by operation of law, without the intervention of a judicial or administrative authority, is governed by the law of the State of the habitual residence of the child.

2. The attribution or extinction of parental responsibility by an agreement or a unilateral act, without intervention of a judicial or administrative authority, is governed by the law of the State of the child's habitual residence at the time when the agreement or unilateral act takes effect.

3. Parental responsibility which exists under the law of the State of the child's habitual residence subsists after a change of that habitual residence to another State.

4. If the child's habitual residence changes, the attribution of parental responsibility by operation of law to a person who does not already have such responsibility is governed by the law of the State of the new habitual residence.

Article 17

The exercise of parental responsibility is governed by the law of the State of the child's habitual residence. If the child's habitual residence changes, it is governed by the law of the State of the new habitual residence.

Article 18

The parental responsibility referred to in Article 16 may be terminated, or the conditions of its exercise modified, by measures taken under this Convention.

Article 19

1. The validity of a transaction entered into between a third party and another person who would be entitled to act as the child's legal representative under the law of the State where the transaction was concluded cannot be contested, and the third party cannot be held liable, on the sole ground that the other person was not entitled to act as the child's legal representative under the law designated by the provisions of this Chapter, unless the third party knew or should have known that the parental responsibility was governed by the latter law.

2. The preceding paragraph applies only if the transaction was entered into between persons present on the territory of the same State.

Article 20

The provisions of this Chapter apply even if the law designated by them is the law of a non-Contracting State.

Article 21

1. In this Chapter the term ‘law’ means the law in force in a State other than its choice of law rules.