CC 1248     

Art. 1248.  Advantages other than donation.

The advantage which a father bestows upon his son, though in any other manner than by donation or legacy, is likewise subject to collation.  Thus, when a father has sold a thing to his son at a very low price, or has paid for him the price of some purchase, for [or] has spent money to improve his son's estate, all that is subject to collation.