When this applies
The information was spread, it is untrue, and it harms the reputation. All three conditions must be present together.
The burden of proof
Under article 100 of the Civil Code, the person who spread the information must prove that it is true. For the injured person this is a real relief.
What you can demand
A retraction through the court (if a mass medium spread the information — in that same medium); the chance to speak in your own defence in that same mass medium; compensation for damages and for moral harm; replacement or withdrawal of a document, if the information is in a document of an organisation.
Evidence
If the information was spread on the internet, have the page certified by a notary, or record a screenshot with the date — the material can be deleted.