The owners of a software’s copyright have been for more than ten years in a legal battle with a former client’s unauthorised use. In the end, the Court of Cassation decided in the rights holders’ favour. The Court emphasised the written-form process by stating that any transfer of an author’s exclusive rights must be supported by drafted strictly in written form; otherwise, the rights are presumed not to have been transferred. This decision strengthens the protection given to authors by requiring assignees to specify in writing the precise range of the transferred rights. From this point on, in the absence of a written agreement, the rights of the original author are retained, and it belongs to the presumed assignee to prove that the disputed rights have been transferred.