Artikel 56

1. The application of the provisions of Articles 52 to 54 as between two or more Contracting Parties shall be subject to the conclusion between those Parties of bilateral or multilateral agreements which may also contain appropriate special arrangements.
2. The agreements referred to in the preceding paragraph shall specify in particular:
(a) the categories of persons to whom the provisions of Articles 52 to 54 shall apply;
(b) the period during which benefits may be paid by the institution of one Contracting Party, the cost being borne by the institution of another Contracting Party;
(c) arrangements for the refund of benefits provided by the institution of one Contracting Party where the cost is to be borne by the institution of another Contracting Party.
3. Two or more Contracting Parties may agree that there shall be no refunds between the institutions in their jurisdiction.