U+2101 · Other symbol
Addressed To The Subject Symbol ℁
℁ is addressed to the subject, U+2101. Unicode records it as a compatibility form of a/s (compat form). It was added in Unicode 1.1, and Unicode files it under Other symbol.
Also known as
- aux soins (de)
Codes & technical data
| Unicode | U+2101 | |
|---|---|---|
| HTML hex | ℁ | |
| HTML decimal | ℁ | |
| CSS | \2101 | |
| JavaScript | \u{2101} | |
| Python | \U00002101 | |
| Java / C# | \u2101 | |
| Rust | \u{2101} | |
| Swift | \u{2101} | |
| PHP | \u{2101} | |
| URL encoded | %E2%84%81 | |
| UTF-8 bytes | E2 84 81 | |
| UTF-16 bytes | 2101 | |
| Base64 | 4oSB | |
| Decimal | 8449 | |
| Decomposes to | a/s (compat form) | |
| Category | Other symbol (So) | |
| Introduced | Unicode 1.1 | |
Will ℁ survive being pasted?
- Normalisation. No. Anything that applies NFKC — search indexes, usernames, domain names, programming identifiers — rewrites ℁ as
a/s. Safe for display, not for storage. - Legacy encodings. ℁ is Unicode-only — it has no Latin-1 equivalent, so a system stuck on an 8-bit encoding cannot represent it.
- Size. 3 bytes in UTF-8. Character-limited fields — SMS, bios, some form validators — usually count bytes, not characters.
Unicode cross-references
The standard points readers of ℁ at these characters — usually because they look alike, or because one is the correct choice where the other is often used by mistake.
Nearby in Letterlike Symbols
Characters built out of letters but treated as symbols — ℃ ℉ №, the trademark and service marks, and the script and blackletter letters that mathematics uses as distinct variables. Most normalise back to plain letters, which is worth knowing before pasting one into a password field.
How to type ℁
| Windows | Type 2101 then press Alt+X |
|---|---|
| macOS | Press Ctrl+Cmd+Space, then search for “addressed to the subject” |
| Linux | Press Ctrl+Shift+U, type 2101, press Enter |
| HTML | ℁ |
About Unicode’s Other symbol category
Unicode files this under "other symbol" — the catch-all for pictographs, signs and marks that are neither maths, currency, nor letter-like. It is the largest symbol category in the standard.
Frequently asked questions
- How do I type the ℁ addressed to the subject symbol?
- On Windows, type 2101 and press Alt+X. On Linux press Ctrl+Shift+U then 2101. On any system the quickest route is the copy button on this page.
- What is the code for ℁?
- Addressed To The Subject is U+2101. In UTF-8 it takes 3 bytes. The table above lists every escape format.
- Will ℁ survive being pasted anywhere?
- Not always. Addressed To The Subject is a compatibility character: any system that applies Unicode NFKC normalisation — search indexes, usernames, identifiers — replaces it with a/s. Use it for display, not where text is normalised.