Article 155 Federal Labor Law

The employees who find themselves in the cases of the preceding article and who aspire to a vacant or newly created position must present an application to the enterprise or establishment indicating their domicile and nationality, whether they have a family in their charge and who depend economically on them, whether they rendered service previously and for what time, the nature of the work they performed and the name of the labor union to which they belong, so that they are called when some vacancy occurs or some new position is created; or present themselves to the enterprise or establishment at the moment the vacancy occurs or the position is created, proving the cause on which they base their application.