Комментарий к Шмот 30:26

ומשחת בו AND THOU SHALT ANOINT WITH IT — All anointings mentioned in Scriptures were made in the form of a Greek X except the anointing of kings which were made round the head like a crown (wreath) (Keritot 5b).

Anointings were done in the form of the Greek chi. . . כ"י means a Greek chi, which looks like a Hebrew נ .