Mathematical Double-Struck Capital S 𝕊
Visual Description: The symbol is a stylized S drawn with two parallel vertical lines that extend above and below the curves. It looks like a regular S with a bold, double stroke. In many fonts it stands out clearly, especially in math captions and diagrams.
Meaning & Usage: In formulas it can mark a special set or space. It is not a letter for ordinary text, but a symbol to emphasize a concept. You may see it with other double struck letters like N or R in equations. Digital editors let you insert it via a symbol palette or a LaTeX command like \mathbb{S}.
Historical Background: The double struck style came from writing on blackboards, where extra strokes helped to distinguish standard objects. It later appeared in printed math fonts and then in Unicode, so editors can render it consistently. Textbooks and software adopted the symbol for clear, quick notation in complex formulas.
Practical Use: In practice, people use this symbol to name a set or space in formulas. In calculators and math apps you may see a symbol palette or a shortcut to insert it. Quick UI controls help you perform comparisons or denote special objects as you edit equations.
See our category page for related symbols.
Look‑alikes: S (U+53).
Need styled alternatives? Try the Fancy Text tool.
Confusables
Technical details
- Codepoint:
U+1D54A - General Category:
Lu - Age:
3.1 - Bidi Class:
L - Decomposition:
<font> 0053 - Block:
Mathematical Alphanumeric Symbols - Script:
Common - UTF-8:
F0 9D 95 8A - UTF-16:
D835 DD4A - UTF-32:
0001D54A - HTML dec:
𝕊 - HTML hex:
𝕊 - JS escape:
\u{1D54A} - Python \N{}:
\N{MATHEMATICAL DOUBLE-STRUCK CAPITAL S} - Python \U:
\U0001D54A - URL-encoded:
%F0%9D%95%8A - CSS escape:
\1D54A
How to type / insert
Fast copy: click the Copy button near the top of this page.
By codepoint: in many editors and IDEs, you can insert via the Unicode code U+1D54A or a built‑in character picker.
HTML: use the numeric entity 핊 (hex) or 핊 (decimal) when an HTML entity is needed.
Compatibility & troubleshooting
Font support: if the symbol does not render, the current font likely lacks this codepoint. Choose a font with broad Unicode coverage or allow a fallback font.
Web pages: ensure your CSS font stack includes a general fallback; avoid relying on images for common symbols to preserve accessibility and copyability.