Work-to-rule is an industrial action in which employees are entitled to do no more than the minimum required by the rules of their contract, and precisely follow all safety or other regulations, which may cause a slowdown or decrease in productivity, as they are no longer working during breaks or during unpaid extended hours and weekends (checking email, for instance). Such an action is considered less disruptive than a strike or lockout; and obeying the rules is less susceptible to disciplinary action. Notable examples have included nurses refusing to answer telephones, teachers refusing to work for free at night and during weekends and holidays, and police officers refusing to issue citations. Refusal to work overtime, travel on duty, or sign up to other tasks requiring employee assent are other manifestations of using work-to-rule as industrial action.