Libel and slander are concepts derived from the (Dutch) criminal code. These crimes are subject to penalties and even jail sentences, although people rarely go to jail in the Netherlands for libel or slander. So these are criminal law terms, not terms under civil law. But a person guilty of libel or slander is still committing an illegal act. Article 6:162 of the Dutch Civil Code states that “he who commits an illegal act against another is obligated to compensate for the damage suffered by the other”.
Libel concerns those expressions in which one party attempts to ruin another’s reputation: an attempt to sully another person’s good name. Without this being required from the standpoint of a defence, one can be considered to be publicly libelled if one is publicly accused of committing crimes such as theft or fraud. The facts of which one is accused need not be crimes per se. A public accusation of cheating outside marriage can also be criminal (and therefore illegal). When such accusations are made in writing (including accusations made on Internet), this is considered defamation.
Slander involves making public accusations about another person in public, while the person making the accusation should have known that those accusations were not true. The boundary between libel and slander is sometimes difficult to delineate. If you know that something is not true, then it can be slander; if you speak the truth, then it can never be slander. But libel or defamation may be considered to exist, since telling the truth can also be criminal (and therefore illegal). So it’s not simply a question of whether someone is lying or not, but of whether someone’s honour and good reputation are affected by the particular accusation.
Although libel and slander can be reported, these acts rarely result in jail time – at most in a relatively low monetary penalty. For this reason, many victims of libel or defamation (also) choose to take civil legal actions against the perpetrator. If an accusation or suspicion is unlawful, then the injured party is entitled to compensation of damages on the basis of the Civil Code. Various sorts of damage can be suffered. The most important are reputational damage and (for businesses) revenue damages.