What is or was scapulimancy used for?

Question

What name is given to a special day or happening, used variously over centuries to mark important days in a calendar, to mark capitals or rubrics in religious texts, or to wear particular clothing?

Answer 1

Divination
Questions were carved or written onto a bone, in the case of scapulimancy the shoulder blade or scapula of an ox, intense heat was then applied with a metal rod until the bone cracked, and the answer divined from the pattern of the cracks. The oracle bones were used in ancient China, mainly during the late Shang dynasty in the second millennium BCE. As well as ox bone diviners used the undershell, or plastron, of turtles.