The third chapter deals with the distinction between dispositive and mandatory norms. The author highlights the importance of theoretically well-established boundaries in between these two categories of norms since the opposite (rather intuitive) approach might lead to an unequal interpretation of law.
Mandatory norms are more frequent in public law, however, it is not necessary to make a doctrinal link between the mandatory norm and public law. The difference is more subtle and it requires detailed analysis of structure of a norm.
According to the author, the dispositive feature of a norm might arise only from a hypothesis of the norm but not from its disposition. When a norm has the permission in its disposition it is so-called mandatory dispositive norm.
The problem of dispositive norms is that hypothesises do not always include the explicit permission for autonomous regulation and that it is thus necessary to conclude that a norm is dispositive by interpretation.