The collective agreement contains many important provisions concerning the relationship between employers and employees. When a collective agreement applies in the workplace, both employers and employees are bound by it. However, only employers of those two, can take part in the collective agreement, and therefore negotiate the content of it.

The purpose of this study is to answer the following question: Why are rules that has been interpreted in collective agreements not expressed in writing? Therefore, the Swedish collective agreement system will be examined, and a distinction between types of silent regulations will be made to find causes. The potential for workers to act on a collective agreement with quiet regulations will also be examined.

Collective agreements are signed on three levels: central, union and local levels. Expressing interpreted rules in writing in collective agreements at all levels would require much time and money. But a rule that seeks to require the employee obligations, and that is not expressed in writing, may result in the employee commits a collective crime. A collective crime may raise liability to the counterparty.

Interpretation of silent regulations is mainly relevant for the peace obligation. To commence action of conflict is the parties' way to force the result they want of the counterparty. If the parties control all the relations between them in detail to increase the predictability and stability in collective agreement relationships, the reasons for taking actions of conflict are to be fewer and the peace obligation is given greater extent. That the peace obligation is given greater extent is therefore a reason why interpreted rules are not expressed in writing. Silent regulations are to some extent so obvious and accepted obligations that one can assume that the worker has a good sense to recognize the rights and responsibilities he or she has. A reason to bring interpreted rules in collective agreements in writing does therefore not exist.