Bottom cloth radical, a pictograph of a cloth or towel hanging from a sash. Originally
常 referred to a long lower garment — the everyday robe a person wore day in, day out. From 'usual garment' came the modern senses often, common, regular, constant (
常常,
平常,
经常). The radical anchors a textile family:
帽 (hat),
帆 (sail),
帜 (flag).