What ⑀ means
It is a special control mark in OCR-A.
OCR (optical character recognition) lets machines read printed text. OCR-A began as a U.S. numeric font in 1961, expanded to an alphanumeric set in 1966, and was paired with companion OCR-B in ISO 1073 in 1976. It was designed to keep printed data legible to both people and machines.
A 1981 technical standard lists Hook among OCR-A's special control symbols. An agreed interchange application can use it as a stand-in for the ASCII tilde (~); it remains a distinct character.
What if someone sends ⑀ alone?
Treat it as unexplained technical text.
Its documented role is technical. If the sender is discussing OCR-A, a form, or a font, ask which convention they mean; otherwise, do not infer a feeling from the glyph alone.
Technical and specialized; it reads as OCR or typography notation when that context is present.
Do not read a mood into it; the sender's context is missing.
What it means when someone sends it to you
3 readingsDon't confuse it with
4Questions people ask
1Why does the OCR hook look different in my font?
Font choice. Unicode does not prescribe one drawing for ⑀, so fonts may show this text symbol in visibly different forms.
How to type ⑀
⑀\2440Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.