Reference LGR for script: Gujarati (Gujr) lgr-second-level-gujarati-script-15dec20-en

This document is mechanically formatted from the above 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 2020-12-15
LGR Version 1 (Second Level Reference LGR)
Language und-Gujr (Gujarati Script)
Unicode Version 6.3.0

Table of Contents

1 Description

Reference Label Generation Rules for the Gujarati Script

Overview

This document specifies a reference set of Label Generation Rules (LGR) for the Gujarati script for the second level. The starting point for the development of this LGR can be found in the related Root Zone LGR [RZ-LGR-4-Gujr]. For details and additional background on the script, see "Proposal for a Gujarati Script Label Generation Ruleset for the Root Zone" [Proposal-Gujarati]. The format of this file follows [RFC 7940].

Repertoire

This LGR contains 65 code points for letters covering multiple languages written using the Gujarati script and ranging from 1 to 4 on the [EGIDS] scale. The repertoire is a subset of [Unicode 6.3]. For more detail, see Section 5, "Repertoire" in [Proposal-Gujarati]. (The proposal cited has been adopted for the Gujarati script portion of the Root Zone LGR.)

For the second level, the repertoire has been augmented with the Gujarati digits, U+0AR6 to U+0AEF (૯), ASCII digits U+0030 (0) to U+0039 (9), and U+002D (-) HYPHEN-MINUS for a total of 86 repertoire elements.

Each code point or range is tagged with the script or scripts that the code point is used with, one or more tag values denoting character category, and one or more references documenting sufficient justification for inclusion in the repertoire, see "References" below.

Variants

This LGR defines no variants for letters. For details, see Section 6, "Variants" in [Proposal-Gujarati].

Digit Variants: All Gujarati digits are treated as semantic variants of the corresponding common (ASCII) digits. By transitivity, they are also semantic variants of any native digits in scripts that also include the common digits. Such variant relations are deemed to exist implicitly by transitivity but are not listed explicitly in each reference LGR. (Omitting the listing of these other cross script digit variants does not affect index variant calculation, as the ASCII digit variant being smallest would always be the index variant.) Note that in addition to a transitive semantic variant relation, Gujarati digits ZERO, TWO, FOUR, and EIGHT are cross-script homoglyphs or near homoglyphs with Devanagari digits of the same value. Digit FOUR is also a variant of Oriya digit FOUR. Gujarati digit ZERO is a cross-script homoglyph or near homoglyph of digit ZERO in many other scripts; these are already implicit semantic variants by transitivity and therefore not listed here.

Some Gujarati letters share forms with digits: U+0AB0 (ર) GUJARATI LETTER RA is a homoglyph variant of U+0aE8 (૨) GUJARATI DIGIT TWO. U+0AAA (પ) GUJARATI LETTER PA is a homoglyph variant of U+0AEB (૫) GUJARATI DIGIT FIVE. By transitivity, the ASCII digits TWO and FIVE are also variants of the respective letters, and so are all other corresponding native digits TWO and FIVE, even though not explicitly listed here.

To keep digit variant sets manageable in zones where multiple scripts are present, no attempt has been made at identifying cross-script variants among digits of different numeric value, such as between Gujarati digit ONE and Bengali digit SEVEN; or between a digit in one script and a letter in another, such as between digit zero and Latin letter 'o'.

Character Classes

Gujarati is an alphasyllabary and the heart of the writing system is the akshar. This is the unit which is instinctively recognized by users of the script. As encoded, the writing system of Gujarati is composed of Consonants, the Implicit Vowel Killer: Halant, Vowels, Anusvara, Candrabindu, Nukta, Visarga and Avagraha.

Consonants: Gujarati consonants contain an implicit vowel schwa /ə/. The traditional classification categorizes them according to their phonetic properties. There are 5 Varga groups (classes) and one non-Varga group. Each varga, which corresponds to a particular stop, contains five consonants classified as per their properties. The first four consonants are classified on the basis of Voicing and Aspiration and the last is the corresponding nasal. More details in Section 3.4.1, "The Consonants" of the [Proposal-Gujarati].

Halant: All consonants contain the implicit vowel (schwa). A special sign is needed to denote that this implicit vowel is stripped off. This is known as the Halant (્). The Halant thus joins two consonants and creates conjuncts, which generally combine 2 to 4 consonants. In rare cases the Halant can join up to 5 consonants. More details in Section 3.4.2, "The Implicit Vowel Killer: Halant" in [Proposal-Gujarati].

Vowels and Matras: Separate symbols exist for all Vowels, which are either pronounced independently at the beginning or attached to a consonant. To indicate the latter (other than the implicit one), a Vowel modifier (matra) is attached to the consonant. Since the consonant has a built-in schwa, there are equivalent Matras for all vowels excepting the અ (U+0A85). More details in Section 3.4.3, "Vowels" in [Proposal-Gujarati].

Anusvara: In Gujarati, the Anusvara has a dual function. On the one hand, it acts as homorganic nasal, that is, it replaces a conjunct group of a Nasal Consonant+Halant+Consonant belonging to that particular varga. On the other hand, before a non-varga consonant the anusvara represents a nasal sound. Gujarati and its dialects prefer the anusvara to the corresponding half-nasal. More details in Section 3.4.4, "The Anusvara" in [Proposal-Gujarati].

Nukta: Traditionally Gujarati does not admit the Nukta. Gujarati grammarians in their inventory of the Gujarati alphabet do not admit this diacritic. However, the Nukta is used to represent content where Perso-Arabic characters have to be transliterated. It follows specific consonants listed in set C1. More details in Section 3.4.6, "Nukta" in [Proposal-Gujarati].

Visarga and Avagraha: The Visarga is frequently used in Sanskrit and represents a sound very close to /h/, as in દુઃખ /du:kh/ sorrow, unhappiness. It is used sparingly in Gujarati with a few words borrowed from Sanskrit. The Avagraha is rarely used and excluded from the LGR. More details in Section 3.4.7, "Visarga and Avagraha" in [Proposal-Gujarati].

Common Digits: U+0030 (0) to U+0039 (9) are the set of digits from the ASCII range.

Gujarati Digits: U+0AE6 (૦) to U+0AEF (૯) are a set of Gujarati-specific digits.

Whole Label Evaluation (WLE) and Context Rules

Common Rules

Default Actions

Actions include the default actions for LGRs as well as that needed to invalidate labels with misplaced combining marks. They are marked with ⍟. For a description see [RFC 7940].

Gujarati-specific Rules

These rules have been drafted to ensure that the prospective Gujarati label conforms to akshar formation norms as desired in Gujarati script. These norms are exclusively presented as context rules.

The following symbols are used in the WLE rules:
C → Consonant
M → Matra
V → Vowel
B → Anusvara
X → Visarga
H → Halant/Virama
N → Nukta
C1 → Consonants used with Nukta

The rules are:

More details in Section 7,"Whole Label Evaluation Rules (WLE)" in [Proposal-Gujarati].

Methodology and Contributors

This reference LGR for the Gujarati script for the 2nd Level has been developed by Michel Suignard and Asmus Freytag, based on the Root Zone LGR for Gujarati and information contained or referenced therein, see [RZ-LGR-4-Gujr]. Suitable extensions for the second level have been applied according to the [Guidelines]. The original proposal for a Root Zone LGR for the Gujarati script, that this reference LGR is based on, was developed by the Neo-Brahmi Generation Panel (NBGP). For more information on methodology and contributors to the underlying Root Zone LGR, see Sections 4 and 8 in [Proposal-Gujarati], as well as [RZ-LGR-Overview].

References

The following general references are cited in this document:

[Guidelines]
ICANN, "Guidelines for Developing Reference LGRs for the Second Level, (Los Angeles, California: ICANN, 27 May 2020),
https://www.icann.org/en/system/files/files/lgr-guidelines-second-level-06jan16-en.pdf
[EGIDS]
Expanded Graded Intergenerational Disruption Scale,
https://www.ethnologue.com/about/language-status
[Proposal-Gujarati]
Neo-Brahmi Generation Panel, "Proposal for a Gujarati Script Root Zone Label Generation Ruleset (LGR)", 6 March 2019,
https://www.icann.org/en/system/files/files/proposal-gujarati-lgr-06mar19-en.pdf
[RFC 7940]
Davies, K. and A. Freytag, "Representing Label Generation Rulesets Using XML", RFC 7940, August 2016,
http://www.rfc-editor.org/info/rfc7940
[RZ-LGR-Overview]
Integration Panel, "Root Zone Label Generation Rules - LGR-4: Overview and Summary", 5 November 2020 (PDF),
https://www.icann.org/sites/default/files/lgr/lgr-4-overview-05nov20-en.pdf
[RZ-LGR-4-Gujr]
ICANN, Root Zone Label Generation Rules for the Gujarati Script (und-Gujr) , 5 November 2020 (XML)
https://www.icann.org/sites/default/files/lgr/lgr-4-gujarati-script-05nov20-en.xml
[Unicode 6.3]
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/

For references consulted particularly in designing the repertoire for the Gujarati script for the second level please see details in the Table of References below. Reference [0] refers to the Unicode Standard version in which the corresponding code points were initially encoded. Reference [101] corresponds to a source justifying the inclusion of the corresponding code points. Entries in the table may have multiple source reference values. Reference [150] indicates the source for common rules.

2 Repertoire

Repertoire Summary

Number of elements in repertoire 86
Number of code points
for each script
Gujarati 75
Common 11
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.

For any code point or sequence for which a variant is defined, additional information is provided in the Variants column. See also the legend provided below the table.

Code
Point
Glyph Script Name Ref Tags Required Context Variants Comment
U+002D - Common HYPHEN-MINUS [0] Hyphen not: hyphen-minus-disallowed  
U+0030 0 Common DIGIT ZERO [0] Common-digit   set 1
U+0031 1 Common DIGIT ONE [0] Common-digit   set 2
U+0032 2 Common DIGIT TWO [0] Common-digit   set 3
U+0033 3 Common DIGIT THREE [0] Common-digit   set 4
U+0034 4 Common DIGIT FOUR [0] Common-digit   set 5
U+0035 5 Common DIGIT FIVE [0] Common-digit   set 6
U+0036 6 Common DIGIT SIX [0] Common-digit   set 7
U+0037 7 Common DIGIT SEVEN [0] Common-digit   set 8
U+0038 8 Common DIGIT EIGHT [0] Common-digit   set 9
U+0039 9 Common DIGIT NINE [0] Common-digit   set 10
U+0A82 Gujarati GUJARATI SIGN ANUSVARA [0], [101] Anusvara follows-V-C-N-or-M    
U+0A83 Gujarati GUJARATI SIGN VISARGA [0], [101] Visarga follows-V-C-N-or-M    
U+0A85 Gujarati GUJARATI LETTER A [0], [101] Vowel      
U+0A86 Gujarati GUJARATI LETTER AA [0], [101] Vowel      
U+0A87 Gujarati GUJARATI LETTER I [0], [101] Vowel      
U+0A88 Gujarati GUJARATI LETTER II [0], [101] Vowel      
U+0A89 Gujarati GUJARATI LETTER U [0], [101] Vowel      
U+0A8A Gujarati GUJARATI LETTER UU [0], [101] Vowel      
U+0A8B Gujarati GUJARATI LETTER VOCALIC R [0], [101] Vowel      
U+0A8C Gujarati GUJARATI LETTER VOCALIC L [6], [101] Vowel      
U+0A8D Gujarati GUJARATI VOWEL CANDRA E [0], [101] Vowel      
U+0A8F Gujarati GUJARATI LETTER E [0], [101] Vowel      
U+0A90 Gujarati GUJARATI LETTER AI [0], [101] Vowel      
U+0A91 Gujarati GUJARATI VOWEL CANDRA O [0], [101] Vowel      
U+0A93 Gujarati GUJARATI LETTER O [0], [101] Vowel      
U+0A94 Gujarati GUJARATI LETTER AU [0], [101] Vowel      
U+0A95 Gujarati GUJARATI LETTER KA [0], [101] C1, Consonant      
U+0A96 Gujarati GUJARATI LETTER KHA [0], [101] C1, Consonant      
U+0A97 Gujarati GUJARATI LETTER GA [0], [101] C1, Consonant      
U+0A98 Gujarati GUJARATI LETTER GHA [0], [101] Consonant      
U+0A99 Gujarati GUJARATI LETTER NGA [0], [101] Consonant      
U+0A9A Gujarati GUJARATI LETTER CA [0], [101] Consonant      
U+0A9B Gujarati GUJARATI LETTER CHA [0], [101] Consonant      
U+0A9C Gujarati GUJARATI LETTER JA [0], [101] C1, Consonant      
U+0A9D Gujarati GUJARATI LETTER JHA [0], [101] Consonant      
U+0A9E Gujarati GUJARATI LETTER NYA [0], [101] Consonant      
U+0A9F Gujarati GUJARATI LETTER TTA [0], [101] Consonant      
U+0AA0 Gujarati GUJARATI LETTER TTHA [0], [101] Consonant      
U+0AA1 Gujarati GUJARATI LETTER DDA [0], [101] Consonant      
U+0AA2 Gujarati GUJARATI LETTER DDHA [0], [101] Consonant      
U+0AA3 Gujarati GUJARATI LETTER NNA [0], [101] Consonant      
U+0AA4 Gujarati GUJARATI LETTER TA [0], [101] Consonant      
U+0AA5 Gujarati GUJARATI LETTER THA [0], [101] Consonant      
U+0AA6 Gujarati GUJARATI LETTER DA [0], [101] Consonant      
U+0AA7 Gujarati GUJARATI LETTER DHA [0], [101] Consonant      
U+0AA8 Gujarati GUJARATI LETTER NA [0], [101] Consonant      
U+0AAA Gujarati GUJARATI LETTER PA [0], [101] Consonant   set 6  
U+0AAB Gujarati GUJARATI LETTER PHA [0], [101] C1, Consonant      
U+0AAC Gujarati GUJARATI LETTER BA [0], [101] Consonant      
U+0AAD Gujarati GUJARATI LETTER BHA [0], [101] Consonant      
U+0AAE Gujarati GUJARATI LETTER MA [0], [101] Consonant      
U+0AAF Gujarati GUJARATI LETTER YA [0], [101] Consonant      
U+0AB0 Gujarati GUJARATI LETTER RA [0], [101] Consonant   set 3  
U+0AB2 Gujarati GUJARATI LETTER LA [0], [101] Consonant      
U+0AB3 Gujarati GUJARATI LETTER LLA [0], [101] Consonant      
U+0AB5 Gujarati GUJARATI LETTER VA [0], [101] Consonant      
U+0AB6 Gujarati GUJARATI LETTER SHA [0], [101] Consonant      
U+0AB7 Gujarati GUJARATI LETTER SSA [0], [101] Consonant      
U+0AB8 Gujarati GUJARATI LETTER SA [0], [101] Consonant      
U+0AB9 Gujarati GUJARATI LETTER HA [0], [101] Consonant      
U+0ABC Gujarati GUJARATI SIGN NUKTA [0], [101] Nukta follows-specific-C    
U+0ABE Gujarati GUJARATI VOWEL SIGN AA [0], [101] Matra follows-C-or-N    
U+0ABF િ Gujarati GUJARATI VOWEL SIGN I [0], [101] Matra follows-C-or-N    
U+0AC0 Gujarati GUJARATI VOWEL SIGN II [0], [101] Matra follows-C-or-N    
U+0AC1 Gujarati GUJARATI VOWEL SIGN U [0], [101] Matra follows-C-or-N    
U+0AC2 Gujarati GUJARATI VOWEL SIGN UU [0], [101] Matra follows-C-or-N    
U+0AC3 Gujarati GUJARATI VOWEL SIGN VOCALIC R [0], [101] Matra follows-C-or-N    
U+0AC4 Gujarati GUJARATI VOWEL SIGN VOCALIC RR [0], [101] Matra follows-C-or-N    
U+0AC5 Gujarati GUJARATI VOWEL SIGN CANDRA E [0], [101] Matra follows-C-or-N    
U+0AC7 Gujarati GUJARATI VOWEL SIGN E [0], [101] Matra follows-C-or-N    
U+0AC8 Gujarati GUJARATI VOWEL SIGN AI [0], [101] Matra follows-C-or-N    
U+0AC9 Gujarati GUJARATI VOWEL SIGN CANDRA O [0], [101] Matra follows-C-or-N    
U+0ACB Gujarati GUJARATI VOWEL SIGN O [0], [101] Matra follows-C-or-N    
U+0ACC Gujarati GUJARATI VOWEL SIGN AU [0], [101] Matra follows-C-or-N    
U+0ACD Gujarati GUJARATI SIGN VIRAMA [0], [101] Halant follows-C-or-N    
U+0AE6 Gujarati GUJARATI DIGIT ZERO [0] Gujarati-digit   set 1  
U+0AE7 Gujarati GUJARATI DIGIT ONE [0] Gujarati-digit   set 2  
U+0AE8 Gujarati GUJARATI DIGIT TWO [0] Gujarati-digit   set 3  
U+0AE9 Gujarati GUJARATI DIGIT THREE [0] Gujarati-digit   set 4  
U+0AEA Gujarati GUJARATI DIGIT FOUR [0] Gujarati-digit   set 5  
U+0AEB Gujarati GUJARATI DIGIT FIVE [0] Gujarati-digit   set 6  
U+0AEC Gujarati GUJARATI DIGIT SIX [0] Gujarati-digit   set 7  
U+0AED Gujarati GUJARATI DIGIT SEVEN [0] Gujarati-digit   set 8  
U+0AEE Gujarati GUJARATI DIGIT EIGHT [0] Gujarati-digit   set 9  
U+0AEF Gujarati GUJARATI DIGIT NINE [0] Gujarati-digit   set 10  

Legend

Code Point
A code point or code point sequence.
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.
Name
Shows the character or sequence name from the Unicode Character Database.
Ref
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 a rule defining the required context a code point or sequence must satisfy. If prefixed by “not:” identifies a context that must not occur.
Variants
Link to the variant set the code point or sequence is a member of, except where a coded point or sequence maps only to itself, in which case the type of that mapping is listed.
Comment
The comment as given in the XML file. However, if the comment for this row consists only of the code point or sequence name, it is suppressed in this view. By convention, comments starting with “=” denote an alias. If present, the symbol ⍟ marks a default item shared among a set of LGRs.

3 Variant Sets

Variant Set Summary

Number of variant sets 10
Largest variant set 3
Variants by Type
blocked 28

The following tables list all variant sets defined in this LGR, except for singleton sets. Each table lists all variant mapping pairs of the set; one per row. Mappings are assumed to be symmetric: each row documents both forward (→) and reverse (←) mapping directions. In each table, the mappings are sorted by Source value in ascending code point order; shading is used to group mappings from the same source code point or sequence.

Where the type of both forward and reverse mappings are the same, a single value is given in the Type column; otherwise the types for forward and reverse mappings, as well as comments and references, are listed above one another. For summary counts, both forward and reverse mappings are always counted separately.

In any LGR with variant specifications that are well behaved, all members within each variant set are defined as variants of each other; the mappings in each set are symmetric and transitive; and all variant sets are disjoint.

Common Legend

Source
By convention, the smaller of the two code points in a variant mapping pair.
Target
By convention, the larger of the two code points in a variant mapping pair.
Glyph
The shape displayed for source or target depends on the fonts available to your browser.
- forward
Indicates that Type, Ref and Comment apply to the mapping from source to target.
- reverse
Indicates that Type, Ref and Comment apply to the reverse mapping from target to source.
- both
Indicates that Type, Ref and Comment apply to both forward and reverse mapping.
Type
The type of the variant mapping. There are some predefined variant types such as “allocatable” and “blocked”, while others are defined specifically for each LGR.
Ref
One or more reference IDs (optional). A “/” separates references for reverse / forward mappings, if different.
Comment
A descriptive comment (optional). A “/” separates comments for reverse / forward mappings, if different.

Variant Set 1 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0030 0 0AE6 blocked   ASCII digit variant / Gujarati digit variant

Variant Set 2 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0031 1 0AE7 blocked   ASCII digit variant / Gujarati digit variant

Variant Set 3 — 3 Members

Source Glyph Target Glyph   Type Ref Comment
0032 2 0AB0 blocked   ASCII digit variant / Gujarati variant
0032 2 0AE8 blocked   ASCII digit variant / Gujarati digit variant
0AB0 0AE8 blocked   Gujarati variant / Gujarati digit variant

Variant Set 4 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0033 3 0AE9 blocked   ASCII digit variant / Gujarati digit variant

Variant Set 5 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0034 4 0AEA blocked   ASCII digit variant / Gujarati digit variant

Variant Set 6 — 3 Members

Source Glyph Target Glyph   Type Ref Comment
0035 5 0AAA blocked   ASCII digit variant / Gujarati variant
0035 5 0AEB blocked   ASCII digit variant / Gujarati digit variant
0AAA 0AEB blocked   Gujarati variant / Gujarati digit variant

Variant Set 7 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0036 6 0AEC blocked   ASCII digit variant / Gujarati digit variant

Variant Set 8 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0037 7 0AED blocked   ASCII digit variant / Gujarati digit variant

Variant Set 9 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0038 8 0AEE blocked   ASCII digit variant / Gujarati digit variant

Variant Set 10 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0039 9 0AEF blocked   ASCII digit variant / Gujarati digit variant

4 Classes, Rules and Actions

4.1 Character Classes

The following table lists all named and implicit 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
C Tag=Consonant 34 {0A95-0AA8 0AAA-0AB0 0AB2-0AB3 0AB5-0AB9}   Any Gujarati consonant
V Tag=Vowel 14 {0A85-0A8D 0A8F-0A91 0A93-0A94}   Any Gujarati vowel letter
M Tag=Matra 13 {0ABE-0AC5 0AC7-0AC9 0ACB-0ACC}   Any Gujarati vowel sign
N Tag=Nukta 1 {0ABC}   The Gujarati Nukta
C1 Tag=C1 5 {0A95-0A97 0A9C 0AAB}   Consonants used with Gujarati Nukta
common-digits Tag=Common-digit 10 {0030-0039}   Digits from the ASCII range; ⍟
gujarati-digits Tag=Gujarati-digit 10 {0AE6-0AEF}   Gujarati digits
hyphen Tag=Hyphen 1 {002D}   The Hyphen-minus character ⍟
implicit Tag=Anusvara 1 {0A82}   The character tagged as Anusvara
implicit Tag=Halant 1 {0ACD}   The character tagged as Halant
implicit Tag=Visarga 1 {0A83}   The character tagged as Visarga
implicit Tag=sc:Gujr 75 {0A82-0A83 0A85-0A8D 0A8F-0A91 0A93-0AA8 0AAA-0AB0 0AB2-0AB3 0AB5-0AB9 0ABC 0ABE-0AC5 0AC7-0AC9 0ACB-0ACD 0AE6-0AEF}   Any character tagged as Gujarati
implicit Tag=sc:Zyyy 11 {002D 0030-0039}   Any character tagged as Common

Legend

Members or Ranges
Lists the members of the class as code points (xxx) or as ranges of code points (xxx-yyy). Any class too numerous to list in full is elided with "...".
Tag=ttt
A named or implicit class defined by all code points that share the given tag value (ttt).
Implicit
An anonymous class implicitly defined based on tag value for which there is no named equivalent.

4.2 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 or variant.

Name Regular Expression Used as
Trigger
Anchor Used as
Context
Ref Comment
leading-combining-mark (start)[[\p{gc=Mn}] ∪ [\p{gc=Mc}]]     [150] RFC 5891 restrictions on placement of combining marks ⍟
hyphen-minus-disallowed (((start))← ⚓)|(⚓ →((end)))|(((start)..[:hyphen:])← ⚓)   C [150] RFC 5891 restrictions on placement of U+002D (-) ⍟
follows-specific-C ([:C1:])← ⚓   C   Section 7, WLE 1: N must be preceded by a specific set of Cs
follows-C-or-N ([:C:]|[:N:])← ⚓   C   Section 7, WLE 2: Halant must be preceded by C or N; WLE 5: M: must be preceded by C or N
follows-V-C-N-or-M ([:V:]|[:C:]|[:N:]|[:M:])← ⚓   C   Section 7, WLE 3 and WLE 4: Visarga and Anusvara must be preceded by V, C, N or M
digit-mixing ([:common-digits:].*[:gujarati-digits:])|([:gujarati-digits:].*[:common-digits:])       restrictions on mixing digits

Legend

Used as Trigger
This rule triggers one of the actions listed below.
Used as Context
This rule defines a required or prohibited context for a code point C or variant V.
Anchor
This rule has a placeholder for the code point for which it is evaluated.
Regular Expression
A regular expression equivalent to the rule, shown in a modified notation as noted:
⚓ - context anchor
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.
(... | ...) - choice
When there is more than one alternative in a rule, the choices are separated by the alternation operator (...|...).
start or end
(start) matches the start of the label; (end) matches the end of the label.
. - any code point
. matches any code point.
*, +, ?, {n,m} - count operators
* indicates 0 or more, + indicates one or more, and ? indicates up to one instance. {n,m} indicates at least n and at most m instances.
[: :] - named or implicit character set
Reference to a named character set [:name:] or an implicit character set [:tag:]. A leading “^” before name or tag indicates the set complement.
[\p{ }] - property character set
Set of all characters matching a given value for a Unicode property [\p{prop=val}]. Note: uppercase “\P” defines the complement of a property set.
∪, ∩, ∖, ∆ - set operators
Sets may be combined by set operators ( = union, = intersection, = difference, = symmetric difference).
⍟ - default rule
Rules marked with ⍟ are included by default and may or may not be triggered by any possible label under this LGR.

4.3 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 [150] labels with leading combining marks are invalid ⍟
2 if label matches digit-mixing invalid   a label violating the restriction on digit mixing is invalid
3 if at least one variant is in {out-of-repertoire-var} invalid   any variant label with a code point out of repertoire is invalid ⍟
4 if at least one variant is in {blocked} blocked   any variant label containing blocked variants is blocked ⍟
5 if each variant is in {allocatable} allocatable   variant labels with all variants allocatable are allocatable ⍟
6 if any label (catch-all)   valid   catch all (default action) ⍟

Legend

{...} - variant type set
In the “Rule/Variant Set” column, the notation {...} means a set of variant types.
⍟ - default action
Actions marked with ⍟ are included by default and may or may not be triggered by any possible label under this LGR.

5 Table of References

The following lists the references cited for specific code points, variants, classes, rules or actions in this LGR. For General references refer to the "References" section in the Description.

[0] The Unicode Standard 1.1
Any code point originally encoded in Unicode 1.1
[6] The Unicode Standard 4.0
Any code point originally encoded in Unicode 4.0
[101] Omniglot, "Gujarati",
https://www.omniglot.com/writing/gujarati.htm
(Accessed on 6 Jan. 2018)
[150] RFC 5891, Internationalized Domain Names in Applications (IDNA): Protocol
http://tools.ietf.org/html/rfc5891