The sums paid into a retirement savings plan may come from :
1° Voluntary payments by the holder ;
2° Sums paid under the profit-sharing scheme provided for in Title II of Book III of Part III of the Labour Code, or under the incentive scheme provided for in Title I of Book III of the Labour Code, or from payments by companies provided for in Title III of Book III of the Labour Code, as well as from rights registered in the time savings account or, in the absence of a time savings account in the company and within limits set by decree, from sums corresponding to days of rest not taken, in the case of company retirement savings plans;
3° Compulsory payments by the employee or the employer, in the case of company retirement savings plans to which the employee is a compulsory member.