All property, whether movable or immovable, is deemed to be acquired by the community unless it is proved that it belongs to one of the spouses by application of a provision of the law.
If the property is one which does not in itself bear proof or mark of its origin, the personal ownership of the spouse, if it is contested, must be established in writing. In the absence of an inventory or other pre-constituted evidence, the judge may take into consideration any written documents, in particular family titles, registers and domestic papers, as well as bank documents and invoices. He may even admit proof by testimony or presumption, if he finds that a spouse was materially or morally unable to obtain a writing.