LGR for language rus-Cyrl — Russian

This document is mechanically formatted from the XML file for the LGR. It provides additional summary data and explanatory text. The XML file remains the sole normative specification of the LGR.

Date 2016-08-30
LGR Version 1
Language rus-Cyrl
Unicode Version 6.3.0


Label Generation Rules for Russian


This document specifies a reference set of Label Generation Rules for Russian using a limited repertoire as appropriate for a second level domain.


All references converge on 33 Cyrillic code points (23 +10 as defined by RFC 5992 [130]).

There is an IDN table published in the IANA Repository of IDN Practices for Russian by .ru (Russia cctld) [700]. There are other new Cyrillic TLDs created in Russia, but they all use the same repertoire as .ru.

In Russian, the acute accent may be used as a stress mark on the vowel of a syllable or to disambiguate between minimal pairs. However, it is restricted to dictionaries and educational materials. See Stress and Disambiguation in [ACUTE].

Four code points: U+0456 (і) CYRILLIC SMALL LETTER BYELORUSSIAN-UKRAINIAN I, U+0463 (ѣ) CYRILLIC SMALL LETTER YAT, U+0473 (ѳ) CYRILLIC SMALL LETTER FITA, and U+0475 (ѵ) CYRILLIC SMALL LETTER IZHITSA were abolished from use in 1918; therefore they are not in modern use.

Excluded code points

Letters documented in some references but not included:

Extended code points




Note: a study of the variant relationship concerning U+0435 (е) CYRILLIC SMALL LETTER IE and U+0451 (ё) CYRILLIC SMALL LETTER IO was undertaken in the context of Russian by a Cyrillic case study team in [CYRILLIC-VIP]. The expert team concluded: "...even if relationships between these two characters might look as variant-like, they are not symmetrical and these two letters are not considered equivalents in Russian language." (page 5, section 3.1)

Character Classes

This LGR defines no named character classes.


Common rules only:


Actions included are the default actions for LGRs as well as those needed to invalidate labels with misplaced combining marks.

Variant-related actions included to facilitate integration as appropriate.

Methodology and Contributors

This reference LGR for Russian for the 2nd Level has been developed by Michel Suignard and Asmus Freytag, verified in expert reviews by Michael Everson, Nicholas Ostler, and Wil Tan, and based on multiple open public consultations.


General references for the language:

Other references cited in this document:

Wikipedia, "Acute accent"
Sozonov, A. et al., “IDN Variant TLDs – Cyrillic Script Issues”. (Marina del Rey, California: ICANN, October 2011).

In the listing of the repertoire by code point, references starting from [0] refer to the version of the Unicode Standard in which the corresponding code point was initially encoded. Other references, (starting from [100]) document usage of code points. For more details, see the Table of References below.



Number of elements in Repertoire 44
Total entries in table 44
Longest code point sequence 1

Repertoire by Code Point

The following table lists the repertoire by code point (or code point sequence). The data in the Script and Name column are extracted from the Unicode character database. Where a comment in the original LGR is equal to the character name, it has been suppressed.

Glyph Script Name References Tags Required Context Part of
U+002D - Common HYPHEN-MINUS [0] sc:Zyyy not: hyphen-minus-disallowed  
U+0030 0 Common DIGIT ZERO [0] sc:Zyyy    
U+0031 1 Common DIGIT ONE [0] sc:Zyyy    
U+0032 2 Common DIGIT TWO [0] sc:Zyyy    
U+0033 3 Common DIGIT THREE [0] sc:Zyyy    
U+0034 4 Common DIGIT FOUR [0] sc:Zyyy    
U+0035 5 Common DIGIT FIVE [0] sc:Zyyy    
U+0036 6 Common DIGIT SIX [0] sc:Zyyy    
U+0037 7 Common DIGIT SEVEN [0] sc:Zyyy    
U+0038 8 Common DIGIT EIGHT [0] sc:Zyyy    
U+0039 9 Common DIGIT NINE [0] sc:Zyyy    
U+0430 а Cyrillic CYRILLIC SMALL LETTER A [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0431 б Cyrillic CYRILLIC SMALL LETTER BE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0432 в Cyrillic CYRILLIC SMALL LETTER VE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0433 г Cyrillic CYRILLIC SMALL LETTER GHE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0434 д Cyrillic CYRILLIC SMALL LETTER DE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0435 е Cyrillic CYRILLIC SMALL LETTER IE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0436 ж Cyrillic CYRILLIC SMALL LETTER ZHE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0437 з Cyrillic CYRILLIC SMALL LETTER ZE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0438 и Cyrillic CYRILLIC SMALL LETTER I [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0439 й Cyrillic CYRILLIC SMALL LETTER SHORT I [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043A к Cyrillic CYRILLIC SMALL LETTER KA [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043B л Cyrillic CYRILLIC SMALL LETTER EL [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043C м Cyrillic CYRILLIC SMALL LETTER EM [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043D н Cyrillic CYRILLIC SMALL LETTER EN [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043E о Cyrillic CYRILLIC SMALL LETTER O [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+043F п Cyrillic CYRILLIC SMALL LETTER PE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0440 р Cyrillic CYRILLIC SMALL LETTER ER [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0441 с Cyrillic CYRILLIC SMALL LETTER ES [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0442 т Cyrillic CYRILLIC SMALL LETTER TE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0443 у Cyrillic CYRILLIC SMALL LETTER U [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0444 ф Cyrillic CYRILLIC SMALL LETTER EF [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0445 х Cyrillic CYRILLIC SMALL LETTER HA [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0446 ц Cyrillic CYRILLIC SMALL LETTER TSE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0447 ч Cyrillic CYRILLIC SMALL LETTER CHE [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0448 ш Cyrillic CYRILLIC SMALL LETTER SHA [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0449 щ Cyrillic CYRILLIC SMALL LETTER SHCHA [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044A ъ Cyrillic CYRILLIC SMALL LETTER HARD SIGN [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044B ы Cyrillic CYRILLIC SMALL LETTER YERU [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044C ь Cyrillic CYRILLIC SMALL LETTER SOFT SIGN [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044D э Cyrillic CYRILLIC SMALL LETTER E [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044E ю Cyrillic CYRILLIC SMALL LETTER YU [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+044F я Cyrillic CYRILLIC SMALL LETTER YA [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    
U+0451 ё Cyrillic CYRILLIC SMALL LETTER IO [0], [100], [130], [201], [301], [401], [700] sc:Cyrl    


Code Point
A code point or code point sequence.
Shows the character or sequence name from the Unicode Character Database.
The shape displayed depends on the fonts available to your browser.
Shows the script property value from the Unicode Character Database. Combining marks may have the value Inherited and code points used with more than one script may have the value Common.
Links to the references associated with the code point or sequence, if any.
LGR-defined tag values. Any tags matching the Unicode script property are suppressed in this view.
Required Context
Link to the rule defining the required context a code point or sequence must satisfy. If prefixed by "not:", identifies a context that must not occur.
If the comment in this row consists only of the code point or sequence name it is suppressed in this view.
✔ - core repertoire
A check mark in the Part-of-Repertoire column indicates a code point is part of the core repertoire.

Variant Sets

This LGR does not specify any variants.

Classes, Rules and Actions

Character Classes

The following table lists all named classes with their definition and a list of their members intersected with the current repertoire (for larger classes, this list is elided).

Name Definition Count Members or Ranges Ref Comment
implicit Tag=sc:Cyrl 33 Elements: {0430-044F 0451}    
implicit Tag=sc:Zyyy 11 Elements: {002D 0030-0039}    


Members or Ranges
Lists the members of the class as code points (xxx) or ranges of code points (xxx-yyy). Any class too numerous to list in full is elided with "...".
A named class is defined by all code points that share the given tag value (ttt).
An anonymous class implicitly defined class based on tag value.

Whole label evaluation and context rules

The following table lists all named rules defined in the LGR and indicates whether they are used as trigger in an action or as context (when or not-when) for a code point. (Any use of context rules for variants is not indicated).

Name Used as
Used as
Anchor Regular Expression Ref Comment
leading-combining-mark     (^[∅=[[∅=\p{gc=Mn}][∅=\p{gc=Mc}]]]) [120] RFC5891 restrictions on placement of combining marks
hyphen-minus-disallowed   ((((?<=^)⚓)|(⚓(?=$))|((?<=^..\u002D)⚓))) [120] RFC5891 restrictions on placement of U+002D
extended-cp       (^$)   code points from the extended range


Used as Trigger
This rule triggers one of the actions listed below.
Used as Context
This rule defines a required context for a code point.
This has a place holder for the code point for which it is evaluated.
Regular Expression
A regular expression equivalent to the rule, shown in the standard notation with some extensions as noted:
⚓ - context anchor
In a regex the ⚓ signifies a placeholder for the actual code point, when a context is evaluated. The code point must occur at the position corresponding to the anchor. Rules containing an anchor cannot be used as triggers.
(?<=...) - look-behind
If present encloses required context preceding the anchor.
(?=...) - look-ahead
If present encloses required context following the anchor.
[\p{ }] - property character set
A character set defined by reference to a value for a given Unicode property [\p{prop=val}]. A set defined via "\P" indicates the set complement.
[&&,-,^] - set operators
Sets may be combined by set operators (&& = intersection, - = difference, ^ = symmetric difference) or concatenated (union).
∅= - empty set
Indicates that the following set is empty because of the result of set operations, or because none of its elements are part of the repertoire defined here. A rule with a non-optional empty set never matches.
(^$) - empty label
The regex (^$) matches the empty label. Used as a context rule, it always fails to match, thus disallowing the affected code point in any label. By convention, it is used for context rules that disable code points that are not part of the repertoire, yet explicitly listed in the LGR as excluded or for optional future extension.

Note: The following rules are defined but not used in this LGR: extended-cp.


The following table lists the actions that are used to assign dispositions to labels and variant labels, based on the specified conditions. The order of actions defines their precedence: the first action triggered by a label is the one defining its disposition.

# Condition Rule / Variant Set   Disposition Ref Comment
1 if label matches leading-combining-mark invalid   by default, labels with leading combining marks are invalid
2 if any label (catch-all)   valid   catch all (default action)


{...} - variant type set
In the "Rule/Variant Set" column the notation {...} means a set of variant types.

Table of References

[0] The Unicode Consortium. The Unicode Standard, Version 6.3.0, (Mountain View, CA: The Unicode Consortium, 2013. ISBN 978-1-936213-08-5)
Any code point cited was originally encoded in Unicode Version 1.1
[100] Internetstiftelsen i Sverige (IIS), Russian
[120] RFC5891, Internationalized Domain Names in Applications (IDNA): Protocol
[130] RFC5992, Internationalized Domain Names Registration and Administration Guidelines for European Languages Using Cyrillic - section 2.7 Russian
[201] Omniglot Russian
[301] Everson, Michael, The Alphabets of Europe, Russian
Code points cited form the standard set
[304] Everson, Michael, The Alphabets of Europe, Russian
Code points cited are rare or archaic
[401] The Unicode Consortium, Common Locale Data Repository - CLDR Version 28 (2015-09-16) - Locale Data Summary for Russian [ru]-
Code points cited are from the set of Main Letters
[700] Coordination Center for TLD RU (.ru Russia cctld)