This is the protection that employers get to join a trade union and participate in collective bargaining without fear of retribution or different treatment by the organization. 

Each organization must ensure to associate themselves with a trade union; this does not only protect the employee but also the employer in an instance where a redundancy has to be carried out or where the employee feels they have been dismissed unfairly.  Some organizations add the trade unions they are associated with as an advantage to make them stand out  and an employee benefit.