Visitors ask...What Do the Initials "I.N.R.I." on a Crucifix Stand For?

Fisheaters.com states:

You also might see a representation of the titulus crucis -- the plaque marked with "I.N.R.I." which stands for "Iesus Nazarenus Rex Iudeorum," the Latin initials for "Jesus of Nazareth, King of the Jews." This inscription was written in Latin, Hebrew, and Greek and placed at the top of Jesus' Cross according to Matthew 27:37, Mark 15:26, Luke 23:38 and John 19:19.

In truth, the "u" was probably written as a "v". You can find more on Wikipedia if you are interested.