"Not an open shop" is a phrase used to describe workplaces where employees are not required to join a union or pay union dues. Other phrases that can be used to describe such workplaces include "non-union shop," "unorganized workplace," and "agency shop." These workplaces are often viewed as more employer-friendly, as they offer flexibility and autonomy for both employers and employees. However, unions argue that workers in such workplaces have less bargaining power and are at a disadvantage when it comes to negotiating better wages and benefits. Ultimately, the choice of whether or not to join a union should be left up to the individual worker.