Library employees may also be represented by a union. Almost any type of union may attempt to organize a library. The American Federation of State, County and Municipal Employees(AFSCME) represents many public-sector employees. Depending on the size and nature of the bargaining unit, library employees may be part of a larger unit or may have a separate library employee bargaining unit. The union may also represent only certain groups or classes of library employees. In such cases, the management-employee relationship is governed somewhat by the union contract agreed to by both parties.