The employment contract covers the rights and obligations of the employer and employee. The employee undertakes to perform the agreed work and the employer is obliged to pay wages and social security contributions and to permit holidays. As a minimum, the employment contract must contain the names of both parties (employer and employee), the date the contract starts, the work to be performed and the wage to be paid. Frequently other laws or regulations, particularly the Swiss Code of Obligations and the Collective Working Agreements, govern other aspects not detailed by the parties in the contract.