LGR for language isl-Latin — Icelandic

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 isl-Latin
Unicode Version 6.3.0

Description

Label Generation Rules for Icelandic

Overview

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

Repertoire

All references converge on 36 Latin code points for the essential repertoire.

There is no IDN table published in the IANA Repository of IDN Practices for the .is ccTLD, but the registry provides IDN information [700]. For Icelandic there exists a source, "Nordic Cultural Requirements", [501]-[504], that explicitly addreses the repertoire needed for IT purposes. It presents four categories of letters, from "essential" to "rare".

Excluded code points

Letters documented in some references but not included:

Extended code points

None.

The four letters 'c', 'q', 'w' and 'z' do not form part of the modern alphabet, the first three being only used in words of foreign origin. Nevertheless, the relevant standard, [501], explicitly considers them part of the "essential" set, and they are thus included in the core repertoire. The references consulted diverge strongly on candidates for other extended code points, therefore, this LGR selects none.

Variants

None.

Character Classes

This LGR defines no named character classes.

Rules

Common rules only:

Actions

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

Methodology and Contributors

This reference LGR for Icelandic 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.

References

General references for the language:

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.

Repertoire

Summary

Number of elements in Repertoire 47
Total entries in table 47
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.

Code
Point		 Glyph Script Name References Tags Required Context Part of
Repertoire		 Comment
U+002D - Common HYPHEN-MINUS [0], [100], [301], [401], [501], [601] sc:Zyyy not: hyphen-minus-disallowed ✔  
U+0030 0 Common DIGIT ZERO [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0031 1 Common DIGIT ONE [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0032 2 Common DIGIT TWO [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0033 3 Common DIGIT THREE [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0034 4 Common DIGIT FOUR [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0035 5 Common DIGIT FIVE [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0036 6 Common DIGIT SIX [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0037 7 Common DIGIT SEVEN [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0038 8 Common DIGIT EIGHT [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0039 9 Common DIGIT NINE [0], [100], [301], [401], [501], [601] sc:Zyyy   ✔  
U+0061 a Latin LATIN SMALL LETTER A [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0062 b Latin LATIN SMALL LETTER B [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0063 c Latin LATIN SMALL LETTER C [0], [100], [301], [402], [501], [600] sc:Latn   ✔  
U+0064 d Latin LATIN SMALL LETTER D [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0065 e Latin LATIN SMALL LETTER E [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0066 f Latin LATIN SMALL LETTER F [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0067 g Latin LATIN SMALL LETTER G [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0068 h Latin LATIN SMALL LETTER H [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0069 i Latin LATIN SMALL LETTER I [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006A j Latin LATIN SMALL LETTER J [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006B k Latin LATIN SMALL LETTER K [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006C l Latin LATIN SMALL LETTER L [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006D m Latin LATIN SMALL LETTER M [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006E n Latin LATIN SMALL LETTER N [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+006F o Latin LATIN SMALL LETTER O [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0070 p Latin LATIN SMALL LETTER P [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0071 q Latin LATIN SMALL LETTER Q [0], [100], [301], [402], [501], [600] sc:Latn   ✔  
U+0072 r Latin LATIN SMALL LETTER R [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0073 s Latin LATIN SMALL LETTER S [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0074 t Latin LATIN SMALL LETTER T [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0075 u Latin LATIN SMALL LETTER U [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0076 v Latin LATIN SMALL LETTER V [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0077 w Latin LATIN SMALL LETTER W [0], [100], [301], [402], [501], [600] sc:Latn   ✔  
U+0078 x Latin LATIN SMALL LETTER X [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+0079 y Latin LATIN SMALL LETTER Y [0], [100], [301], [401], [501], [601] sc:Latn   ✔  
U+007A z Latin LATIN SMALL LETTER Z [0], [100], [301], [402], [501], [600] sc:Latn   ✔  
U+00E1 á Latin LATIN SMALL LETTER A WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00E6 æ Latin LATIN SMALL LETTER AE [0], [100], [200], [301], [401], [501], [603], [604], [700] sc:Latn   ✔  
U+00E9 é Latin LATIN SMALL LETTER E WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00ED í Latin LATIN SMALL LETTER I WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00F0 ð Latin LATIN SMALL LETTER ETH [0], [100], [301], [401], [501], [603], [604], [700] sc:Latn   ✔  
U+00F3 ó Latin LATIN SMALL LETTER O WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00F6 ö Latin LATIN SMALL LETTER O WITH DIAERESIS [0], [100], [200], [301], [401], [501], [603], [604], [700] sc:Latn   ✔  
U+00FA ú Latin LATIN SMALL LETTER U WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00FD ý Latin LATIN SMALL LETTER Y WITH ACUTE [0], [100], [200], [301], [401], [501], [604], [700] sc:Latn   ✔  
U+00FE þ Latin LATIN SMALL LETTER THORN [0], [100], [301], [401], [501], [603], [604], [700] sc:Latn   ✔  

Legend

Code Point
A code point or code point sequence.
Name
Shows the character or sequence name from the Unicode Character Database.
Glyph
The shape displayed depends on the fonts available to your browser.
Script
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.
References
Links to the references associated with the code point or sequence, if any.
Tags
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.
Comment
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:Latn 36 Elements: {0061-007A 00E1 00E6 00E9 00ED 00F0 00F3 00F6 00FA 00FD-00FE}    
implicit Tag=sc:Zyyy 11 Elements: {002D 0030-0039}    

Legend

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 "...".
Tag=ttt
A named class is defined by all code points that share the given tag value (ttt).
Implicit
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
Trigger		 Used as
Context		 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

Legend

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.
Anchor
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.

Actions

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

Legend

{...} - 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)
http://www.unicode.org/versions/Unicode6.3.0/
Code points cited were originally encoded in Unicode Version 1.1
[100] Internetstiftelsen i Sverige (IIS), "IDN Reference table for Icelandic language"
https://github.com/dotse/IDN-ref-tables/blob/master/language-tables/icelandic-lang-ref-table.txt
[120] RFC5891, Internationalized Domain Names in Applications (IDNA): Protocol
http://tools.ietf.org/html/rfc5891
[200] ISO/IEC 6937 Third Ed. 2001-12-17- Information technology — Coded graphic character set for text communication — Latin alphabet: Table D.1 (p 35) Use of Latin alphabetic characters.
This table lists only the characters outside the set a-z
[301] Everson, Michael. The Alphabets of Europe: "Icelandic"
http://www.evertype.com/alphabets/icelandic.pdf
Code points cited form the standard set
[302] Everson, Michael. The Alphabets of Europe: "Icelandic"
http://www.evertype.com/alphabets/icelandic.pdf
Code points cited are from an extended set
[304] Everson, Michael. The Alphabets of Europe: "Icelandic"
http://www.evertype.com/alphabets/icelandic.pdf
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 Icelandic [is]
http://www.unicode.org/cldr/charts/28/summary/is.html
Code points cited are from the set of Main Letters
[402] The Unicode Consortium, Common Locale Data Repository (CLDR) Version 28 (2015-09-16) - Locale Data Summary for Icelandic [is]
http://www.unicode.org/cldr/charts/28/summary/is.html
Code points cited are from the Auxiliary set
[501] Íslensk málnefnd. 1992. in Icelandic Council for Standardization. 1992. Nordic cultural requirements on information technology. Reykjavík: Staðlaráð Íslands. ISBN 9979-9004-3-1
Code points cited are of category 1: Letters essential for the language
[502] Íslensk málnefnd. 1992. in Icelandic Council for Standardization. 1992. Nordic cultural requirements on information technology. Reykjavík: Staðlaráð Íslands. ISBN 9979-9004-3-1
Code points cited are of category 2: Letters commonly used, but not essential
[503] Íslensk málnefnd. 1992. in Icelandic Council for Standardization. 1992. Nordic cultural requirements on information technology. Reykjavík: Staðlaráð Íslands. ISBN 9979-9004-3-1
Code points cited are of category 3: Letters used for names, in common practice
[504] Íslensk málnefnd. 1992. in Icelandic Council for Standardization. 1992. Nordic cultural requirements on information technology. Reykjavík: Staðlaráð Íslands. ISBN 9979-9004-3-1
Code points cited are of category 4: Letters that are rarely used
[600] Table "Reduced usage of the letters of the ISO Basic Latin alphabet (A-Z) in Wikipedia: "Latin alphabets"
https://en.wikipedia.org/wiki/Latin_alphabets accessed 2015-10-31.
Code points cited are based on an ommitted from the baslic Latin set A-Z according to he table
[601] Table "Reduced usage of the letters of the ISO Basic Latin alphabet (A-Z) in various alphabets " in Wikipedia: "Latin alphabets" in
https://en.wikipedia.org/wiki/Latin_alphabets accessed 2015-10-31.
Code points cited from the basic Latin set A-Z are included in the alphabet according to the table.
[603] ISO/IEC 646:1991 — Information technology — ISO 7-bit coded character set for information interchange
Code points cited are supported in a national edition of ISO-646.
[604] Wikipedia: "Icelandic orthography"
https://en.wikipedia.org/wiki/Icelandic_orthography
[700] isnic. "Registration of IDN names"
https://www.isnic.is/is/news/view?id=41
Code points cited are the non-ASCII code points listed by the registry for the .is domain