The wrapping 勹 forms the upper-right enclosure and serves as the indexing radical. Historically the graph showed a banner with streamers, but the curling outline was reanalyzed as 勹, placing 勿 in the wrap-radical family alongside 包 and 匆.
The two slanting strokes inside the wrap depict streamers or banner-tails flapping. They function as a visual marker showing motion within the enclosure, completing the prohibition-banner image that gives 勿 its 'do not' meaning.
