Mapping of Unicode graphic characters

Main article: Mapping of Unicode characters

By far the most common Unicode characters are graphical characters. Graphical characters all have some visual representation or glyphs associated with them. While Unicode does not specify the concrete glyphs for these characters, it does specify recommended or prototypical glyphs. The actual glyph used by textual display software will depend on the font files used and whether those fonts provide support for contextual and non-contextual glyph variations

Unihan characters

Main article: Unihan

Han unification is the process used by the authors of Unicode and the Universal Character Set to map multiple character sets of the CJK languages into a single set of unified characters. The Chinese characters are common to Chinese (where they are called hanzi), Japanese (where they are called kanji), and Korean (where they are called hanja). Modern Korean, Chinese and Japanese typefaces may represent a given Han character as somewhat different glyphs. However, in the formulation of Unicode, these different glyphs were treated as the same character. This unification is referred to as "Han unification", with the resulting character repertoire sometimes referred to as Unihan.

Besides the Unihan ideographs, Han unification also provides Han unified punctuation, symbols, numerals, ideograph stroke characters and ideographic description characters.

Phonetic characters

Main article: Unicode Phonetic Symbols

Unicode includes letters and marks from the International Phonetic Alphabet (IPA) and those supporting other phonetic writing systems as well.

Numerals

Main article: Unicode numerals

Numerals (often called numbers in Unicode) are characters that denote a number. The same Arabic-Indic numerals are used widely in various writing systems throughout the world and all share the same semantics for denoting numbers, However, the glyphs representing these numerals differ widely from one writing system to another. To support these glyph differences, Unicode includes duplicate encodings of these numerals within many of the script blocks. These digits are repeated in 22 separate blocks — twice in Arabic. Six additional sets of the ten decimal digits repeat again as rich text forms in the mathematical alphanumerics block within the supplementary multilingual plane (i.e., requiring 4 bytes of disk space to store each character).

Unicode also includes several less common numerals: Roman numerals, counting rod numerals, Cuneiform numerals and ancient Greek numerals.

Numerals invariably involve composition of glyphs as a limited number of characters are composed to make other numerals. For example the sequence 9 - 9 - 0 in Arabic-Indic numerals composes the numeral for nine hundred and ninety (990). In Roman numerals, the same number is expressed by the composed numeral Ⅹↀ or ⅩⅯ. Each of these is a distinct numeral for representing the same abstract number. The semantics of the numerals differ in particular in their composition. The Arabic-Indic decimal digits are positional-value compositions, while the Roman numerals are sign-value and they are additive and subtractive depending on their composition.

Punctuation and diacritics

Unicode includes several blocks for unified diacritics and other combining marks and also blocks for unified punctuation. However, when a mark or punctuation character is intended primarily for use within a particular script, the character is assigned to that particular script’s blocks. Therefore authors will find these types of characters throughout the Unicode character database. Unicode categorizes them as:

• Punctuation

• connector (Pc)
• dash (Pd)
• open (Po)
• close (Pe)
• initial (Pi)
• final (Pf)

• Mark

• non-spacing (Mn)
• spacing-combining (Mc)
• enclosing (Me)

Symbols

Unicode has dozens of blocks dedicated to symbols that are useful regardless of one’s writing system. Other script-specific symbols are often included within a particular script’s blocks. Symbols are categorized as:

Symbols:

• math (Sm)
• currency (Sc)
• modifier (Sk)
• other (So)

Music notation

Unicode devotes a block of 256 characters for musical symbols. Since Unicode focuses on characters laid out in two dimensions, these characters do not encode pitch or other parts of Western music expressed in the vertical dimension. Therefore the music symbols are more suited for discussions of music symbols themselves or to discuss rhythm within the prose of a document. To encode more complex musical information some other data format is necessary, such as MusicXML or Midi.