Small Ideographic Comma

It has the ideographic comma’s punctuation role in a smaller compatibility form.

A compatibility character preserves distinctions needed by older encodings. Unicode links this small-form set to CNS 11643, a Chinese character-set standard, and maps ﹑ to U+3001 、. Fonts may show the smaller form differently; NFKC normalization can erase that distinction.

The ordinary comma’s history is much older than FE51: a Japanese National Diet Library reference cites 、 in a Nara-period manuscript copied before 745. Chinese uses it between list items; Japanese uses it for pauses and clause boundaries. Korean layout guidance specifies ideographic punctuation for vertical text, while horizontal Korean generally uses the Latin comma.

Why does it look different from 、?

Its size reflects a compatibility form, not a different punctuation job.

Unicode cross-references FE51 with U+3001 and ︑. A 2004 discussion says small forms were added so older Chinese double-byte character data could be converted to Unicode and back without losing its form. It calls their typographic status unclear and suggests a possible link to marginal punctuation in traditional vertical Chinese text; that origin remains a possibility, not a fact.

Should I use ﹑ in new text?

Usually no; use 、 unless the exact source character matters.

For new text, choose 、. Keep ﹑ only when a source file or conversion test requires the exact code point; ordinary readers need no extra distinction.