Ideographic Annotation Bottom Mark

It marks the lower point in a kanbun reading sequence.

Kanbun means reading Classical Chinese texts with Japanese word order; kaeriten (“return marks”) guide the reordering. ㆘ marks the lower point in an upper–middle–lower sequence, alongside ㆖ and ㆗; ㆑ and numbered marks belong to the same annotation family.

The tradition drew on Chinese text glossing and reached Japanese Buddhist and scholarly reading through Korea. Surviving annotated Japanese manuscripts from the late eighth century attest the wider practice; that date does not date ㆘ itself.

Why does ㆘ look like a box?

A box usually means the font lacks this glyph.

Kanbun marks are positioned alongside vertical source text. Font coverage and layout support vary, so ㆘ can appear as a box or in an awkward place without changing the reading instruction.