The Greek spelling of the name Jesus ‘IHCOYC’ is abbreviated as IHC; when translated into Latin as ‘IHSOUS’ the abbreviation is IHS.
Both versions can be found although the latter abbreviation is the most common when engraved on gravestones. It is a symbol of the Holy Name of Jesus.
IHS is also an abbreviation of the Latin Phrase in hoc signo meaning, in this sign and is most often used when part of the anagram of the Latin phrase, In Hoc Signo Vinces meaning, in this sign you shall conquer. It is most often seen on family crests, military memorials and symbols of the Knights Templar.