Ontologies are today widely used in many different domains with the goal to clarify them and, with the development of semantic Web, to make them available across the Internet community. The legal domain has also been explored concerning ontologies, both on the general as on the sub-domain level. In this paper are explored problems of formal ontology development regarding areas in specific legislation acts that are understated or unequally described across the act. An example of such a problematic act is shown. For ontology implementation, a well-known tool, Protege, is used. The ontology is made in formal way, using PAL - Protege axiom language, for expressing constraints, where needed