Letterlike Symbols is a Unicode block containing 80 characters which are constructed mainly from the glyphs of one or more letters . In addition to this block, Unicode includes full styled mathematical alphabets , although Unicode does not explicitly categorize these characters as being "letterlike."
6-432: Variation selectors may be used to specify chancery (U+FE00) vs roundhand (U+FE01) forms, if the font supports them: The remainder of the set is at Mathematical Alphanumeric Symbols . The Letterlike Symbols block contains two emoji : U+2122 and U+2139. The block has four standardized variants defined to specify emoji-style (U+FE0F VS16) or text presentation (U+FE0E VS15) for the two emoji, both of which default to
12-410: A rich text attribute. For other glyph substitution, the author's intent may need to be encoded with the text and cannot be determined contextually. This is the case with character/glyphs referred to as gaiji , where different glyphs are used for the same character either historically or for ideographs for family names. This is one of the gray areas in distinguishing between a glyph and a character: If
18-470: A family name differs slightly from the ideograph character it derives from, then is that a simple glyph variant or a character variant? Character substitutions may also occur outside of Unicode, for example with OpenType Layout tags. As of Unicode version 16.0, standardized variation sequences specifically for emoji/text presentation are defined for base characters in twenty blocks: Other standardized variation sequences are formed with base characters in
24-604: A text presentation. The following Unicode-related documents record the purpose and process of defining specific characters in the Letterlike Symbols block: Variation selectors A variant form is an alternate glyph for a character, encoded in Unicode through the mechanism of variation sequences : sequences in Unicode that consist of a base character followed by a variation selector character. A variant form usually has
30-581: A very similar appearance and meaning as its base form. The mechanism is intended for variant forms where, generally, if the variant form is unavailable, displaying the base character does not change the meaning of the text, and may not even be noticeable to many readers. Unicode defines two types of variation sequences: Variation selector characters reside in several Unicode blocks: Variation selectors are not required for Arabic and Latin cursive characters, where substitution of glyphs can occur based on context: glyphs may be connected together depending on whether
36-498: The character is the initial character in a word, the final character, a medial character or an isolated character. These types of glyph substitution are easily handled by the context of the character with no other authoring input involved. Authors may also use special-purpose characters such as joiners and non-joiners to force an alternate form of glyph where it would not otherwise appear. Ligatures are similar instances where glyphs may be substituted simply by turning ligatures on or off as
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