IHS

This symbol looked like a dollar sign at first glance. Its origins are Christian rather than monetary, however, and it is sometimes referred to as a Christogram. Some say the words stand for Iesus Hominum Salvator (which means "Jesus, Savior of Men). It could also stand for an abbreviation of the term In Hoc Signo Vinces, or "In This Sign You Will Conquer". According to legend, the first Christian emperor, Constantine I, saw this motto in a dream or vision, accompanied with the sign of the cross, just before he was to fight an epic battle. The most simple and likely of explanations is that the first three letters of Jesus' name in Greek are IHS, and this is a symbol of devotion to him.