ANSWER
The letters "INRI" stand for "Iesus Nazarenus Rex Iudaeorum", which is Latin for "Jesus of Nazareth, King of the Jews".
According to "The Gospel according to John", the actual inscription was written out, not abbreviated, in three languages: Hebrew, Greek, and Latin. The source of the inscription was Pontius Pilate, the Roman governor of Judea. It was customary in the Roman Empire to place an inscription over the cross signifying the crime for which the person was being crucified.
WHO GOT IT RIGHT: Allan Christensen, and Steve Shuba.
