Enclosed Alphanumerics

Enclosed alphanumerics is a Unicode block of typographical symbols of an alphanumeric within a circle, a bracket or other not-closed enclosure, or ending in a full stop. There is another block for these characters (U+1F100—U+1F1FF), encoded in the Supplementary Multilingual Plane, which contains the set of Regional Indicator Symbols as of Unicode 6.0.

Purpose

Many of these characters were originally intended for use as bullets for lists.^[3] The parenthesized forms are historically based on typewriter approximations of the circled versions.^[3] Although these roles have been supplanted by styles and other markup in "rich text" contexts, the characters are included in the Unicode standard "for interoperability with the legacy East Asian character sets and for the occasional text context where such symbols otherwise occur."^[3] The Unicode Standard considers these characters to be distinct from characters which are similar in form but specialized in purpose, such as the circled C, P or R characters which are defined as copyright and trademark symbols or the circled a used for an at sign.^[3]

Unicode chart

Emoji

The Enclosed Alphanumerics block contains one emoji: U+24C2.^[4][5]

It defaults to a text presentation and has two standardized variants defined to specify emoji-style (U+FE0F VS16) or text presentation (U+FE0E VS15).^[6][7]

Additional enclosed alphanumerics

The uses of "black" and "white" below assume that the characters are part of black text on a white background.

• The Dingbat Unicode block includes 1 through 10 as "negative circled [serif] digits" and "negative circled sans-serif digits" (solid circles containing white digits) and "circled sans-serif digits" (digits surrounded by hollow circles).
• Enclosed CJK Letters and Months includes circled 21 through 50, and black squares containing 10, 20, 30, 40, 50, 60, 70 and 80.
• Enclosed Alphanumeric Supplement, in the Supplementary Multilingual Plane, includes white letters in black circles and squares and black letters in squares.
• Letterlike Symbols includes the sound recording copyright symbol ℗ (a circled capital P).
• Latin-1 includes the copyright symbol © (a circled capital C) and registered trademark symbol ® (a circled capital R).
• Transport and Map Symbols includes the information source sign 🛈 (a circled lowercase i).
• Basic Latin includes the at sign @ (a nearly-circled lowercase a).

The Mathematical Operators section of Unicode includes enclosed versions of some common symbols and punctuation marks.

References

1. ↑ "Unicode character database". The Unicode Standard. Retrieved 22 March 2013. 
2. ↑ The Unicode Standard Version 1.0, Volume 1. Addison-Wesley Publishing Company, Inc. 1990–1991. ISBN 0-201-56788-1. 
3. 1 2 3 4 The Unicode Standard, 6.0.1
4. ↑ "UTR #51: Unicode Emoji". Unicode Consortium. 2015-11-12. 
5. ↑ "UCD: Emoji Data for UTR #51". Unicode Consortium. 2015-11-11. 
6. ↑ "Unicode Character Database: Standardized Variants". The Unicode Consortium. 
7. ↑ "Unicode Character Database: Standardized Variation Sequences". The Unicode Consortium.