Dependence on the sponsor ("kafeel") naturally creates room for violations of the rights of foreign workers. Debt causes workers to work for a certain period of time without a salary to cover these fees. This bondage encourages the practice of international labour migration as women in situations of poverty are able to find jobs overseas and pay off their debts through work. It is common for the employer or the sponsor to retain the employee's passport and other identity papers as a form of insurance for the amount an employer has paid for the worker's work permit and airfare. Kafeels sell visas to the foreign worker with the unwritten understanding that the foreigner can work for an employer other than the sponsor.