List of Unicode properties

The Unicode standard not only encodes a very large number of characters, but also defines a number of properties for each of these characters that describe the character and its behavior. For example, one can see from the properties of the letter Ä that it is a capital letter, that the corresponding lower case letter is ä or that it can be broken down into an A with a trema .

General

Formally, Unicode properties are defined as the mapping of code points into a certain range of values. The data is made available in various simple text files and as an XML file.

values

Different value ranges are possible depending on the property. Most properties are listing properties, their range of values ​​consists of a fixed set. Listed properties are further subdivided into catalog properties and binary properties. Catalog properties are characterized by the fact that the number of possible values ​​increases gradually with new Unicode versions. Binary properties are enumerating properties with exactly two values, true ( Y) and false ( N). It is thus indicated whether the property applies to this character or not.

There are also string properties that each character assign a string of Unicode characters, numeric characteristics that each character assigned a number and other properties that can be assigned to any of these categories.

Default values

Properties have one or more default values ​​for a number of reasons. On the one hand, the standard value is often left out in the tables in order to make them clearer. On the other hand, programs must also be able to deal with text that was created according to a newer Unicode version and therefore also contain characters that were not yet used at the time the program was developed. For enumerating properties, a value is usually defined that is considered the standard, in a few cases there are several standard values ​​that are assigned depending on the block. In the case of binary properties, the default value is always N, i.e. not applicable.

With string properties, the default value is always the character itself.

Aliases

Many properties have one or more aliases in addition to their actual name. Often these are abbreviations. Short aliases are also often specified for the possible values ​​of enumerating properties.

status

Many properties are normative , i.e. binding for programs that work according to the Unicode standard and interpret the property. Other properties, however, are marked as informative and serve only as additional information without a binding character. A group of properties is marked as contributing . These properties should not be used on their own, but have been defined in order to derive other properties from them. They usually identify an exceptional set of characters that would otherwise not be recorded. Finally, there are still provisional properties that were initially included with reservations to see whether they would prove themselves in practice.

Some properties are also marked as deprecated ("obsolete"), these should no longer be used for various reasons, but remain in the Unicode standard for reasons of downward compatibility.

stability

In order to ensure backward compatibility, some properties, once they have been set for a character, are not changed or are changed only in certain previously known ways. For example, it stipulates that the name of a character will never be changed even if it turns out to be incorrect.

properties

The following lists show all Unicode properties, grouped as in the official documentation, for the Unicode 6.3 status. The name of the property, an abbreviated alias name (if available), the status of the property, the type of value range and a description are given.

General

The general properties give a rough overview of the character. They are used, among other things, in regular expressions if they support the query of Unicode properties, as in Perl .

property	Short	status	values	description
Name	na	normative	Others	Name of the character *
Name_Alias		normative	Others	Aliases, mainly used for control characters for which the property Nameremains empty
Block	blk	normative	Catalog	Unicode block in which the character is located
Age	age	normative informative	Catalog	Version in which the character was recorded
General_Category	gc	normative	enumerating	rough breakdown of all characters, see separate section
Script	sc	informative	Catalog	The character's writing system , e.g. Latin, Greek, Cyrillic, etc .; Commonfor characters that are used in several writing systems
Script_Extensions		informative	Others	Writing systems for characters that are used in several systems
White_Space	WSpace	normative	binary	indicates a character as a space
Alphabetic	Alpha	informative	binary	Characters from alphabets
Hangul_Syllable_Type	hst	normative	enumerating	Determination of the syllable blocks in Korean
Noncharacter_Code_Point	NChar	normative	binary	reserved characters
Default_Ignorable_Code_Point	DI	normative	binary	Characters that should be ignored in the display if the program does not support them
Deprecated	Dep	normative	binary	deprecated characters that should no longer be used
Logical_Order_Exception	LOE	normative	binary	Characters that must be swapped with the following characters before the Unicode Collation Algorithm can be used
Variation_Selector	VS	normative	binary	Variant selectors that choose between different display variants of the previous character

^* In addition to individual characters, some character strings also have their own name.

General category

The property General_Categoryis one of the basic properties used both in the Unicode standard itself and in many other technical documentation. It divides all characters into letters, numbers, punctuation and others according to their main use. The following table lists the possible values.

category	code	meaning	Examples
Letter	L
Capital letter	Lu	Capital letter	A , Ä , Δ , DŽ
Lowercase letter	Ll	Lowercase letter	a, ä, δ, dž
Title letter	Lt	Characters that are in title notation. These are just a few characters that encode a digraph	Dž
Modifying letter	Lm	Letters that modify the preceding letter	Letters from the Unicode block Spacing Modifier Letters
Other letter	Lo	Letters from alphabets that are not case-sensitive (e.g. Hebrew), CJK and others	ב , 丌
COMBINING SIGN	M
without feed	Mn	Combining character that is placed on or below the preceding character	combining diacritical marks
with feed	Mc	Combining sign that itself takes up space	indian vowel symbols
enclosing	Me	Combining character that completely surrounds the preceding character	Combining enclosing circle
number	N
Digit	Nd	Digits	0, 1
Letter	Nl	Letters that are used as numbers	Ⅲ
Other numerals	No	other numbers, such as superscripts, circled or fractions	², ½, ②
punctuation	P
connecting	Pc	Characters that combine two parts into one word	Underscore
Line	Pd	different dashes: hyphen , dash , etc.	-, -, -
opening	Ps	opening brackets	(, [, {
closing	Pe	closing brackets	),],}
opening quotation mark	Pi	opening quotation marks (can also be used as closing quotes depending on the language)	«
closing quotation mark	Pf	closing quotation mark (can also be used as an opening quote depending on the language)	»
other punctuation	Po	Punctuation marks and other punctuation that do not fall into any of the above categories	! . ,:; ? §
symbol	S
Math symbol	Sm	Symbols used in mathematical contexts	+, <,>, ±
Currency symbol	Sc	Symbols that denote a currency	$, €
Modifying symbol	Sk	Symbols that modify the preceding character	Symbols from the Unicode block Spacing Modifier Letters
Miscellaneous symbol	So	Symbols that do not fall into any of the above categories	⛔, ©
White space	Z
Spaces	Zs	Different width spaces	Space , non-breaking space
new line	Zl		Line separator (U + 2028)
Paragraph break	Zp		Paragraph separator (U + 2029)
Other signs	C
Control characters	Cc	general control characters	BEL
formatting	Cf	Control characters for formatting	conditional hyphen , bidirectional control characters
Surrogates	Cs	Surrogates
Private use	Co	Sign for private use	U + F8FF
unallocated	Cn	Code points to which no character has (yet) been assigned

Upper / lower case

Many properties are case-sensitive. You determine whether a character is an upper or lower case letter, which is the lower case letter for a given upper case letter and vice versa, and more. In order to compare character strings regardless of the spelling, a normal form called case fold is defined. These properties are used, among other things, by the various Unicode casing algorithms .

property	Short	status	values	description
Uppercase	Upper	informative	binary	indicates a character as a capital letter
Lowercase	Lower	informative	binary	indicates a character as a lower case letter
Cased		informative	binary	denotes all characters that are upper, lower or title letters
Simple_Lowercase_Mapping	slc	normative	String	Corresponding lower case letter (if it is a character)
Simple_Titlecase_Mapping	stc	normative	String	corresponding title letter (if it is a character)
Simple_Uppercase_Mapping	suc	normative	String	Corresponding capital letter (if it is a character)
Simple_Case_Folding	scf	normative	String	associated casefold letter (if it is a character)
Lowercase_Mapping	lc	informative	String	corresponding assignments that also contain more complex conversions
Titlecase_Mapping	tc	informative	String
Uppercase_Mapping	uc	informative	String
Case_Folding	cf	normative	String
Soft_Dotted	SD	normative	binary	i, jand similar characters whose period is removed from capitalization and diacritical marks
Case_Ignorable	CI	informative	binary	Characters without meaning for questions about upper and lower case letters
Changes_When_Lowercased	CWL	informative	binary	Characters that change when converted to lower case
Changes_When_Titlecased	CWT	informative	binary	Characters that change when converted to title writing
Changes_When_Uppercased	CWU	informative	binary	Characters that change when converted to uppercase
Changes_When_Casefolded	CWCF	informative	binary	Characters that change when converted to casefold normal form
Changes_When_Casemapped	CWCM	informative	binary	Characters that change with any case change

Numerically

The following properties deal with the numerical properties of characters, especially the number characters in Unicode .

property	Short	status	values	description
Numeric_Value	nv	normative	numerically	numeric value of the character
Numeric_Type	nt	normative	enumerating	Type (decimal, digit, numeric)
ASCII_Hex_Digit	AHex	normative	binary	ASCII characters that are used for hexadecimal digits, that is, 0to 9, ato, fand AtoF
Hex_Digit	Hex	informative	binary	Characters used for hexadecimal digits, including their variants

normalization

A number of properties deal with the different types of normalization of Unicode texts.

property	Short	status	values	description
Canonical_Combining_Class	ccc	normative	enumerating / numeric	specifies which combining characters interact with each other and in which order they should be sorted
Decomposition_Mapping	dm	normative	String	indicates the decomposition of a character
Decomposition_Type	dt	normative informative	enumerating	indicates the type of decomposition (canonical, changes the font / the break behavior / etc.)
Composition_Exclusion	CE	normative	binary	Characters with a canonical decomposition that should not be used in the combined normal forms
Full_Composition_Exclusion	Comp_Ex	normative	binary
FC_NFKC_Closure	FC_NFKC	normatively deprecated	String	associated caseFold -normal if the character only in the caseFold is transferred -normal and then in NFKC
NFC_Quick_Check	NFC_QC	normative	enumerating	Properties that enable a quick test to determine whether a character string is in a certain normal form
NFKC_Quick_Check	NFKC_QC	normative	enumerating
NFD_Quick_Check	NFD_QC	normative	enumerating
NFKD_Quick_Check	NFKD_QC	normative	enumerating
Expands_On_NFC	XO_NFC	normatively deprecated	binary	Characters that become multiple characters when converted to the appropriate normalization form
Expands_On_NFD	XO_NFD	normatively deprecated	binary
Expands_On_NFKC	XO_NFKC	normatively deprecated	binary
Expands_On_NFKD	XO_NFKD	normatively deprecated	binary
NFKC_Casefold	NFKC_CF	informative	String	Characters after conversion to NFKC and then the normal casefold form
Changes_When_NFKC_Casefolded	CWKCF	informative	binary	Characters that change when they are first converted to NFKC and then to the normal casefold form

presentation

The following properties play a role in the appearance of text.

property	Short	status	values	description
Joining_Group	jg	normative	enumerating	determines how or whether a letter connects with its neighbors, see Arabic in Unicode
Joining_Type	jt	normative	enumerating
Join_Control	Join_C	normative	binary	Control characters for ligatures and letter combinations
Line_Break	lb	normative	enumerating	sets the page break behavior for the Unicode line breaking algorithm determines
Grapheme_Cluster_Break	GCB	informative	enumerating	be in the segmentation algorithms of the limits of the determination graphemes , sentences and words used
Sentence_Break	SB	informative	enumerating
Word_Break	WB	informative	enumerating
East_Asian_Width	ea	informative	enumerating	indicates the width of a character, which plays a role in the representation of East Asian texts
Prepended_Concatenation_Mark	PCM	informative	binary	Characters that span the following characters, such as the Syrian abbreviation symbol

Bidi

The following properties are available for displaying bidirectional text .

property	Short	status	values	description
Bidi_Class	bc	normative	enumerating	determines the writing direction in the Unicode bidi algorithm
Bidi_Control	Bidi_C	normative	binary	Bidirectional control character
Bidi_Mirrored	Bidi_M	normative	binary	indicates whether a character must be displayed mirrored in the left-hand text
Bidi_Mirroring_Glyph	bmg	informative	Others	possible mirror image of the sign, e.g. (as a mirror image for ), in some cases no such sign exists
Bidi_Paired_Bracket	bpb	normative	Others	Counterpart of a bracket
Bidi_Paired_Bracket_Type	bpt	normative	enumerating	indicates opening and closing brackets

Identifier

The following properties are one way of defining the characters allowed in identifiers . In contrast to classic programming languages , which only allow ASCII characters, most of the Unicode characters are allowed in identifiers in languages ​​that use these properties. One example of a language whose syntax largely allows this range is JavaScript .

property	Short	status	values	description
ID_Start	IDS	informative	binary	Character that can be at the beginning of an identifier
ID_Continue	IDC	informative	binary	Character that can appear in the following positions in an identifier
XID_Start	XIDS	informative	binary	Character that can be at the beginning of an identifier
XID_Continue	XIDC	informative	binary	Character that can appear in the following positions in an identifier
Pattern_Syntax	Pat_Syn	normative	binary	Characters that can be used in the syntax
Pattern_White_Space	Pat_WS	normative	binary	Characters that should be treated as white space

CJK

Some properties apply to CJK characters. There are also a number of other properties, see the Unihan section .

property	Short	status	values	description
Ideographic	Ideo	informative	binary	CJK mark
IDS_Binary_Operator	IDSB	normative	binary	Ideographic descriptive symbol
IDS_Trinary_Operator	IDST	normative	binary
Unified_Ideographic	UIdeo	normative	binary	Chinese character that can be used in ideographic description sequences
Radical		normative	binary	Radical that can be used in ideographic descriptive sequences

Others

Some properties are mainly used to provide information about a character without being intended for special applications.

property	Short	status	values	description
Math		informative	binary	Mathematical characters in Unicode
Quotation_Mark	QMark	informative	binary	quotation marks
Dash		informative	binary	horizontal lines of different lengths
Hyphen		informatively deprecated	binary	Hyphen and similar characters, was originally used for line breaks and replaced there by the Line_Breakproperty
STerm		informative	binary	Characters that mark the end of a sentence
Terminal_Punctuation	Term	informative	binary	Punctuation marks that usually mark the end of a sentence
Diacritic	Dia	informative	binary	Diacritical mark
Extender	Ext	informative	binary	Characters that extend the preceding letter, such as length characters
Grapheme_Base	Gr_Base	normative	binary	older properties for the determination of graphemes, see Grapheme_Cluster_Breakthe section representation for the newer method Grapheme_Linkcan consist of Canonical_Combining_Classare determined property
Grapheme_Extend	Gr_Ext	normative	binary
Grapheme_Link	Gr_Link	informatively deprecated	binary
Unicode_1_Name	na1	informative	Others	old name in the Unicode version 1.0
ISO_Comment	isc	informatively deprecated	Others	originally used for comments in the ISO 10646 name list, now empty
Indic_Matra_Category		provisionally	enumerating	determines the placement of dependent vowels in Indian scripts
Indic_Syllabic_Category		provisionally	enumerating	determines the structure of the categories of syllable-forming components in Indian scripts

Contributing Properties

These properties are not used alone, but are used to derive other properties from them. Most of the time, these are exceptional quantities that are not covered by the general category.

property	Short	status	values	description
Other_Alphabetic	OAlpha	contributing	binary	For Alphabetic
Other_Default_Ignorable_Code_Point	ODI	contributing	binary	For Default_Ignorable_Code_Point
Other_Grapheme_Extend	OGr_Ext	contributing	binary	For Grapheme_Extend
Other_ID_Start	OIDS	contributing	binary	for backward compatibility of ID_Start
Other_ID_Continue	OIDC	contributing	binary	for backward compatibility of ID_Continue
Other_Lowercase	OLower	contributing	binary	For Lowercase
Other_Math	OMath	contributing	binary	For Math
Other_Uppercase	OUpper	contributing	binary	For Uppercase
Jamo_Short_Name	JSN	contributing	Others	for Name Korean syllable blocks

Unihan

For CJK characters, which were included in Unicode as part of the Han standardization , there is a separate database that provides properties specifically for these characters. The information on the source denotes the character encoding in various national character sets . In addition to the properties listed here, there are a number of other provisional properties that provide further information on pronunciation, meaning, alternative coding, etc.

property	status	values	description
kAccountingNumeric	informative	numerically	numeric value for forgery-proof number characters
kOtherNumeric	informative	numerically	numeric value of a character that is rarely used as a number sign
kPrimaryNumeric	informative	numerically	numeric value of an ordinary number sign
kCompatibilityVariant	normative	String	Normalization of the character if it is a compatibility variant
kIICore	normative	Others	Character that should be present on all systems
kIRG_GSource	normative	Others	Source: China / Singapore
kIRG_HSource	normative	Others	Source: Hong Kong
kIRG_JSource	normative	Others	Source: Japan
kIRG_KPSource	normative	Others	Source: North Korea
kIRG_KSource	normative	Others	Source: South Korea
kIRG_MSource	normative	Others	Source: Macau
kIRG_TSource	normative	Others	Source: Taiwan
kIRG_USource	normative	Others	Source: USA
kIRG_VSource	normative	Others	Source: Vietnam
kRSUnicode	informative	Others	Radical and number of further strokes
kMandarin	informative	Others	Pinyin -Lesart
kTotalStrokes	informative	Others	Number of strokes including radical

swell

• Mark Davis, Ken Whistler: Unicode Standard Annex # 44: Unicode Character Database. (on-line)
• John H. Jenkins, Richard Cook, Ken Lunde: Unicode Standard Annex # 38: Unicode Han Database. (on-line)
• Ken Whistler, Asmus Freytag: Unicode Technical Report # 23: The Unicode Character Property Model. (on-line)
• Eric Muller: Unicode Standard Annex # 42: Unicode Character Database in XML. (on-line)

Individual evidence

1. ↑ perlretut : More on characters, strings, and character classes. Perl documentation at perldoc.perl.org
2. ^ Addison Phillips: Unicode Standard Annex # 34: Unicode Named Character Sequences. (on-line)
3. ↑ ECMAScript Language Specification , 5.1 Edition, 7.6 Identifier Names and Identifiers

Web links

• Unicode Character Database
• Overview of all properties
• Unicode browser of the ICU project (English)
• Graphemica , overview of all properties of a character
• Codepoints , overview of all properties of a character, including search