La. Civ. Code art. 2339
The natural and civil fruits of the separate property of a spouse, minerals produced from or attributable to a separate asset, and bonuses, delay rentals, royalties, and shut-in payments arising from mineral leases are community property. Nevertheless, a spouse may reserve them as his separate property as provided in this Article.
A spouse may reserve them as his separate property by a declaration made in an authentic act or in an act under private signature duly acknowledged. A copy of the declaration shall be provided to the other spouse prior to filing of the declaration.
As to the fruits and revenues of immovables, the declaration is effective when a copy is provided to the other spouse and the declaration is filed for registry in the conveyance records of the parish in which the immovable property is located. As to fruits of movables, the declaration is effective when a copy is provided to the other spouse and the declaration is filed for registry in the conveyance records of the parish in which the declarant is domiciled.
La. C.C. § 2339