Annotation character

It marks an explanation attached to written text.

註 developed as a written-explanation form related to 注. The 說文解字, a dictionary from the Han period, does not list 註; a manuscript of 玉篇, another dictionary, from the Tang period uses it in an explanatory sense. Later studies of old texts and word history place this specialization after the Six Dynasties.

It can label a gloss (a short explanation of a word), a footnote, or an editorial note beside a passage.

註 or 注: which spelling fits?

The compound and language decide; both graphs serve annotation use.

Historically, 注 is the older graph: its original sense was pouring or directing something, later extended to explaining a text. 註 arose as a speech-related form for that written-explanation sense. Taiwan Ministry of Education guidance uses 註釋 and 標註, but distinguishes 註記, 註冊, and 註銷 from 注 words such as 灌注, 注射, and 注意. Here 註冊 means registration and 註銷 means cancellation of registration.

As of 2026, Japanese school-writing guidance uses 注 in annotation words such as 注解 and 注釈; reference works list 註 as a rewrite form. In Japanese school text, 註 can therefore look deliberately traditional.

What does 註 mean when sent alone?

It reads as a cue for a note, not a complete message.

Beside a quoted passage, title, or difficult phrase, it signals that an explanation belongs with that text. Alone, it names a note but supplies no passage or idea for the note to explain, so the recipient may have to ask what it refers to.