穴

口: 窟 窠

冂: 窩 窿

𠄌: 窈

乛: 窘 穹

厂: 竄 窳

丿: 窖 窞 竁 窸 竊 窆 窄

丶: 窗 窨 窕 窵 窮 竅 突 窪
窣

人: 窬 窯

一: 窉 穿 空 窒

十: 窀 究 窺 竇

Above characters begin with the 穴 shape.

Large groups of characters are subsorted first via second element using:
囗⺆凵𠄌
乛厂丿丶
八一丨十
Then via trailing element using:
口山乚
⺆𠃌亅
丿丶㇏乂八小
丨一土十