Except for the cases where the invalidity is relating to the public order: 1.Invalidity may only be invoked by the party in whose favor the same is established by the law. 2.Invalidity may not be invoked by the party causing the same. 3.Invalidity shall be extinguished if the party in whose favor such invalidity is established explicitly or implicitly waives the same.
Interpretation and application must be checked against the official text and current version.