Artikel 9

The effects of the matrimonial property regime on the legal relations between a spouse and a third party are governed by the law applicable to the matrimonial property regime in accordance with the Convention.
Nonetheless, the law of a Contracting State may provide that the law applicable to the matrimonial property regime may not be relied upon by a spouse against a third party where either that spouse or the third party has his habitual residence in its territory, unless -
1. any requirements of publicity or registration specified by that law have been complied with, or
2. the legal relations between that spouse and the third party arose at a time when the third party either knew or should have known of the law applicable to the matrimonial property regime.
The law of a Contracting State where an immovable is situated may provide an analogous rule for the legal relations between a spouse and a third party as regards that immovable.
A Contracting State may specify by declaration the scope of the second and third paragraphs of this Article.