When looking at the rock chamber from above, if the passage is located at the center of the burial chamber, it is called Ryosode-shiki and if the passage is located toward right side or left side, it is called Katasode-shiki.
石室を上から見たとき、羨道が玄室の中央につけられているものを両袖式、羨道が玄室の左右のどちらかに寄せて付けられているものを片袖式と呼ぶ。