What does INRI mean on the Cross

It is an abbreviation for Jesus Nazarenus, Rex Judeorum – Jesus of Nazareth, King of the Jews. In Latin the “I” and “J” are usually interchangeable and ancient Latin did not use the “J” That is why it is INRI not JNRJ. It was common for the Romans to hang a sign above the crucified to indicate the charges against him. The Bible says that Pilate put the charges in Latin, Greek and Hebrew on the sign.  He had this placed this title above Jesus in mockery rather than faith. He also likely knew it would irritate the Jewish leaders, which it did.  But even in his ridicule, Pilate spoke truth.