HOME

TheInfoList




A Unicode block is one of several contiguous ranges of numeric character codes (
code point In character encoding In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardw ...
s) of the
Unicode Unicode, formally the Unicode Standard, is an information technology standard Standard may refer to: Flags * Colours, standards and guidons * Standard (flag), a type of flag used for personal identification Norm, convention or requireme ...

Unicode
character set that are defined by the
Unicode Consortium The Unicode Consortium (legally Unicode, Inc.) is a 501(c)(3) A 501(c)(3) organization is a corporation, trust, unincorporated association, or other type of organization exempt from federal income tax under section 501(c)(3) of Title 26 of the ...
for administrative and documentation purposes. Typically, proposals such as the addition of new glyphs are discussed and evaluated by considering the relevant block or blocks as a whole. Each block is generally, but not always, meant to supply glyphs used by one or more specific languages, or in some general application area such as
mathematics Mathematics (from Greek: ) includes the study of such topics as numbers (arithmetic and number theory), formulas and related structures (algebra), shapes and spaces in which they are contained (geometry), and quantities and their changes (cal ...
,
surveying Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial or three-dimensional positions of points and the distances and angles between them. A land surveying professional is called a land surveyo ...

surveying
, decorative
typesetting on a composing stick on a type case. , letter founder, from the 1728 edition of '' Cyclopaedia, or an Universal Dictionary of Arts and Sciences, Cyclopaedia''. . Typesetting is the composition of Written language, text by means of arranging ph ...
, social forums, etc.


Design and implementation

Unicode blocks are identified by unique names, which use only ASCII characters and are usually descriptive of the nature of the symbols, in
English English usually refers to: * English language English is a West Germanic languages, West Germanic language first spoken in History of Anglo-Saxon England, early medieval England, which has eventually become the World language, leading lan ...

English
; such as "Tibetan" or "Supplemental Arrows-A". (When comparing block names, one is supposed to equate uppercase with lowercase letters, and ignore any whitespace, hyphens, and underbars; so the last name is equivalent to "supplemental_arrows__a" and "SUPPLEMENTALARROWSA". Blocks are
pairwise disjoint Two disjoint sets. In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical anal ...
, that is, they do not overlap. The starting code point and the size (number of code points) of each block are always multiples of 16; therefore, in the hexadecimal notation, the starting (smallest) point is U+''xxx''0 and the ending (largest) point is U+''yyy''F, where ''xxx'' and ''yyy'' are three or more hexadecimal digits. (These constraints are intended to simplify the display of glyphs in Unicode Consortium documents, as tables with 16 columns labeled with the last hexadecimal digit of the code point.) The size of a block may range from the minimum of 16 to a maximum of 65,536 code points. Every assigned code point has a glyph property called "Block", whose value is a character string naming the unique block that owns that point.Unicode glossary
/ref> However, a block may also contain unassigned code points, usually reserved for future additions of characters that "logically" should belong to that block. Code points not belonging to any of the named blocks, e.g. in the unassigned planes 4–13, have the value block="No_block".


Other classifications

Each Unicode point also has a property called "
General CategoryThe Unicode Standard assigns character properties to each code point. These properties can be used to handle "characters" (code points) in processes, like in line-breaking, script direction right-to-left or applying controls. Slightly inconsequently, ...
", that attempts to describes the role of the corresponding symbol in the languages or applications for whose sake it was included in the system. Examples of General Categories are "Lu" (meaning upper-case letter), "Nd" (decimal digit), "Pi" (open-quote punctuation), and "Mn" (non-spacing mark, i.e. a diacritic for the preceding glyph). This division is completely independent of code blocks: the code points with a given General Category generally span many blocks, and do not have to be consecutive, not even within each block. Each code point also has a script property, specifying which
writing system A writing system is a method of visually representing verbal communication Communication (from Latin ''communicare'', meaning "to share" or "to be in relation with") is "an apparent answer to the painful divisions between self and other, p ...
it is intended for, or whether it is intended for multiple writing systems. This, also, is independent of block. In descriptions of the Unicode system, a block may be subdivided into more specific subgroups, such as the "
Chess symbols Chess Symbols is a Unicode block containing characters for chess notations beyond the basic Western chess symbols in the Miscellaneous Symbols block, as well as symbols representing game pieces for xiangqi (Chinese chess). Block History The fol ...
" in the
Miscellaneous Symbols Miscellaneous Symbols is a Unicode block A Unicode block is one of several contiguous ranges of numeric character codes (code point In character encoding terminology, a code point or code position is any of the numerical values that make up t ...
block (not to be confused with the separate
Chess Symbols Chess Symbols is a Unicode block containing characters for chess notations beyond the basic Western chess symbols in the Miscellaneous Symbols block, as well as symbols representing game pieces for xiangqi (Chinese chess). Block History The fol ...
block). Those subgroups are not "blocks" in the technical sense used by the Unicode consortium, and are named only for the convenience of users.


List of blocks

Unicode 14.0 defines 320 blocks: * 164 in plane 0, the Basic Multilingual Plane (in table below: ) * 145 in plane 1, the Supplementary Multilingual Plane () * 6 in plane 2, the Supplementary Ideographic Plane () * 1 in plane 3, the Tertiary Ideographic Plane () * 2 in plane 14 (E in
hexadecimal In mathematics and computing, the hexadecimal (also base 16 or hex) numeral system is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system repres ...
), the Supplementary Special-purpose Plane () * One each in the planes 15 (Fhex) and 16 (10hex), called Supplementary Private Use Area-A and -B ()


Deleted blocks

The Unicode Stability Policy requires that a character, once assigned, may not be moved or removed, although it may be deprecated. This applies to Unicode 2.0 and all subsequent versions. Prior to this, the following former blocks were removed:


References


External links


Official web site of the Unicode Consortium
(English) {{MathematicalSymbolsNotationLanguage
Unicode blocksThis category lists articles on blocks, as defined by the Universal Character Set in Unicode. Unicode, Blocks {{CatAutoTOC ...