Liber Samekh, fully titled Theurgia Goetia Summa, (Congressus Cum Daemone), Sub Figura DCCC, is a ritual written by Aleister Crowley which he used for the purpose of attaining the "Knowledge and Conversation" of his Holy Guardian Angel. Within the A.'.A.'. (specifically for the Grade of Adeptus Minor) it is a Class D document (signifying "official rituals and instruction").