unions' enforcement of exclusive hiring halls, i.e., those in which the employer is bound, by contract, to hire only employees referred to it by the union. The NLRB requires unions to establish clear procedures and to follow those procedures in order to minimize the likelihood that the union would use a hiring hall procedure to exclude non-members or those out of favour with the union from the workplace. On the other hand, the NLRB applies the more deferential standard applied to union decisions generally in the case of non-exclusive hiring halls, i.e., those in which the union has the power to refer applicants for employment but the employer may also hire employees "off the street"; in those cases the union is barred from acting arbitrarily, in bad faith or discriminatorily. Violations The NLRB recognizes a breach of the duty of fair representation as a violation of the National Labor Relations Act. However, because the duty of fair representation was originally created by judicial interpretation, rather than as an express statutory prohibition, employees covered by the National Labor Relations Act may sue their unions directly, without being required to first exhaust any administrative procedures provided under the National Labor Relations Board. The same is true for workers covered by the Railway Labor Act, which does not provide any administrative procedure for pursuing claims against a union. Employees' claims under either Act are governed by a six-month statute of limitations. The NLRB and the courts provide different solutions against unions that breached their duty of fair representation. Because the Board does not usually have the jurisdiction to enforce the collective bargaining agreement or to issue a remedial order against an employer that has violated it, the NLRB often cannot award complete relief to employees. A court, on the other hand, may order an employer to reinstate or pay back pay to an employee if it finds that the employer violated the collective bargaining agreement and may, in some instances, order the union to pay attorneys' fees to a successful plaintiff. These distinctions do not apply to workers covered by the Railway Labor Act since, as noted above, they have no administrative procedures to enforce their rights. A union may, in some limited circumstances, require employees to exhaust any internal appeals procedures provided under the union's constitution before filing suit. Unions and employers may also generally require employees to exhaust their rights under