Article 408.- Appendices to contracts
1. Appendices may be attached to a contract to detail some provisions of the contract. Appendices shall be as effective as the contract. The contents of appendices shall not be contrary to the contents of the contract.
2. In cases where appendices contain provisions contrary to the contractual provisions, such provisions shall not be valid, unless otherwise agreed upon. In cases where the parties accept appendices with provisions contrary to contractual provisions, such contractual provisions shall be considered having been amended.