Contracts for the sale of listed and unlisted Securities may state that the seller reserves the right to repurchase the Securities in return of for the payment of a certain amount during a specified period of time. Such contracts shall include an agreement to deposit the Securities concerned with a Custodian, who shall manage and dispose of them in accordance with the agreement between the seller and the buyer. Such agreement shall be noted in the Securities register. Securities trading rules shall include provisions which regulate such agreements and these agreements shall be excluded from the trading rules for listed Securities. The provisions of article (508) of the Civil Law shall not apply to such contracts.