The initials (L.S.) is an abbreviation of the Latin phrase Locus Sigilli.  Locus Sigilli is Latin for “the place of the seal” and denotes the area on a contract where the seal is to be affixed. By the 19th century, embossed or impressed seals, and the use of the initials L.S., replaced wax seals in most jurisdictions.  We jokingly tell people it means “Legal Signature” when we have trouble remembering the Latin.