See Jacob Z. Lauterbach, “Substitutes for the Tetragrammaton,” Proceedings of the American Academy of Jewish Research (1931), pp. 61–67. I am indebted to Dr. Sol Cohen, Center for Judaic Studies, University of Pennsylvania, for this reference. In Christian scribal practice, too, the Greek words for Kyrios (Lord) and Theos (God) were often abbreviated by simply writing their first and last letters with a line above them, forming the so-called nomina sacra—KS for Kyrios and THS for Theos (see The Anchor Bible Dic-tionary, “Tetragrammaton in the New Testament”).