Where the shape comes from
The crack that split a heated tortoise shell or ox bone when the diviners of the Shang court read the future in it — the very ritual that produced the oracle bone script this whole system descends from. A diviner’s reading of the crack, spoken aloud, gives 占, to divine and later to occupy; a divination performed at the wrong time, in the evening rather than the morning, gives 外, outside, the sense drifting from irregular to external.
汉字 filed under 卜
No published character on HSK Guide is filed under this radical yet. 汉字库.