Root Zone LGR for script: Bengali (Beng) lgr-4-bengali-script-29jun20-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 2020-06-29
LGR Version 4
Language und-Beng
Scope domain: "." (Root)
Unicode Version 6.3.0

Table of Contents

1 Description

Root Zone Label Generation Rules for the Bengali (Bangla) script

Overview

This file contains Label Generation Rules (LGR) for the Bengali (Bangla) script for the Root Zone. This LGR covers Assamese, Bengali, Manipuri and a number of other languages written with the Bengali script. For details and additional background on the script, see "Proposal for a Bengali Script Root Zone Label Generation Ruleset (LGR)" [Proposal-Bengali]. This file is one of a set of LGR files that together form an integrated LGR for the DNS Root Zone [RZ-LGR-4]. The format of this file follows [RFC 7940].

This is a DRAFT document released for public comments and not final. Please see the announcement on the ICANN website for public comments on Root Zone 4 for details on how to submit comments.

Repertoire

The repertoire contains 61 code points for letters, as well as 9 code point sequences, for a total of 70 repertoire elements. Out of the nine sequences: two sequences override a WLE constraint; four sequences were defined for in-script variants; and the other three sequences were defined to restrict U+09BC (়) NUKTA from appearing in any context other than these sequences. Accordingly, while U+09BC (়) is not listed by itself, it brings the total of distinct code points to 62. For more detail, see Section 5, "Repertoire" in [Proposal-Bengali].

The repertoire is based on [MSR-4], which is a subset of Unicode 6.3 [Unicode 6.3].

As part of the Root Zone, this LGR includes neither digits nor the HYPHEN-MINUS.

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. For code points that are part of the repertoire, comments identify the languages using the code point.

Code points outside the Bengali script that are listed in this file are targets for out-of-script variants and are identified by a reflexive (identity) variant of type "out-of-repertoire-var". They do not form part of the repertoire.

Variants

This LGR defines in-script variants and cross-script variants as described in Section 6, "Variants", in [Proposal-Bengali]. There are three in-script variants; two sequence sets and one set for variation of RA. See Section 6.1 of [Proposal-Bengali]. There are four cross-script variants; two sets with Gurmukhi and the other two sets with Devanagari. See Section 6.2 of [Proposal-Bengali].

Variant Disposition: The in-script variant pair U+09B0 (র) / U+09F0 (ৰ) is of type "allocatable", thus allowing access to either user community. All other variants are of type "blocked", making labels that differ only by these variants mutually exclusive: whichever label containing either of these variants is chosen earlier, the other one equivalent variant label should be blocked. There is no preference among these variants.

The specification of variants in the Root Zone LGR follows the guidelines in [RFC 8228].

Character Classes

Consonants: All consonants contain an implicit vowel. More details in Section 3.3.1, "The Consonants" of [Proposal-Bengali].

Hasanta: A special sign is needed whenever the implicit vowel in the preceding consonant is stripped off. This symbol is also known as the Halant or "Virama". More details in Section 3.3.2, "The Implicit Vowel Killer: Hasanta" of [Proposal-Bengali].

Vowels: Separate symbols exist for all "Swara" or Vowels in Bengali, which are pronounced independently either at the beginning of the word or after another vowel or consonant sound. To indicate a Vowel sound other than the implicit one, a Vowel sign (Matra) is attached to the consonant. More details in Section 3.3.3, " Vowels" of [Proposal-Bengali].

Anusvara: The Anusvara represents a homorganic nasal. It replaces a conjunct group of a Nasal Consonant+Halant+Consonant belonging to that particular barga or set. Before a non-barga consonant, the anusvara represents a nasal sound. More details in Section 3.3.4, "The Anusvara" of [Proposal-Bengali].

Candrabindu: Candrabindu denotes nasalization of the preceding vowel as in চাঁদ /cãd/ "moon" (U+099A U+09BE U+0981 U+09A6). This sign with a dot inside the half-moon mark is used as nasalization marker in many Indian scripts. More details in Section 3.3.5, "Nasalization: Candrabindu" of [Proposal-Bengali].

Visarga and Avagraha: The Visarga U+0983 (ঃ) is frequently used in Bengali loanwords borrowed from Sanskrit and represents a sound very close to /h/. More details in Section 3.3.7, "Visarga and Avagraha" of [Proposal-Bengali].

Ya-phala: There are two instances in Bangla where a Hasanta is preceded by a full vowel (U+0985 (অ) BENGALI LETTER A and U+098F (এ) BENGALI LETTER E). More details in Section 3.3.9, "Use of Ya-phala" of [Proposal-Bengali].

Ra-phala and Ref Sequences: RA+Hasanta (Repha or Ra-phala sequences). More details in Section 3.3.10, "Ra-phala and Ref Sequences" of [Proposal-Bengali].

Nukta: Nukta is not listed by itself in the repertoire; it is only included in three sequences. More details in Section 3.3.6, "Nukta" of [Proposal-Bengali].

Zero Width Non-joiner (ZWNJ) and Zero Width Joiner (ZWJ): These are not included in the repertoire. More details in Section 3.3.8, "Zero Width Non-joiner (U+200C) and Zero Width Joiner (U+200D)" of [Proposal-Bengali].

Whole Label Evaluation (WLE) and Context Rules

Default Whole Label Evaluation Rules and Actions

The LGR includes the set of required default WLE rules and actions applicable to the Root Zone and defined in [MSR-4]. They are marked with ⍟. The default prohibition on leading combining marks is equivalent to ensuring that a label only starts with a consonant or vowel.

Bengali-specific Rules

These rules have been formulated as context rules suitable for adoption into an LGR specification.

The following symbols are used in the WLE rules:

The rules are:

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

Methodology and Contributors

The Root Zone LGR for the Bengali script was developed by the Neo-Brahmi Generation Panel (NBGP) the members of which have experience in linguistics and computational linguistics in a wide variety of languages written with Neo-Brahmi scripts. Under the Neo-Brahmi Generation Panel, there are nine scripts belonging to separate Unicode blocks. Each of these scripts has been assigned a separate LGR, with the Neo-Brahmi GP ensuring that the fundamental philosophy behind building each LGR is in sync with all other Brahmi derived scripts. For further details on methodology and contributors, see Sections 4 and 8 in [Proposal-Bengali], as well as [RZ-LGR-4-Overview].

References

The following general references are cited in this document:

[MSR-4]
Integration Panel, "Maximal Starting Repertoire — MSR-4 Overview and Rationale", 7 February 2019
https://www.icann.org/en/system/files/files/msr-4-overview-25jan19-en.pdf
[Proposal-Bengali]
Neo-Brahmi Generation Panel, “Proposal for a Bangla (Bengali) Script Root Zone Label Generation Rule-Set (LGR)”, 20 May 2020,
https://www.icann.org/en/system/files/files/proposal-bangla-lgr-20may20-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.
[RFC 8228]
A. Freytag, "Guidance on Designing Label Generation Rulesets (LGRs) Supporting Variant Labels", RFC 8228, August 2017,
https://www.rfc-editor.org/info/rfc8228
[RZ-LGR-4]
Integration Panel, "Label Generation Rules for the Root Zone — LGR-4", 29 June 2020 (XML),
https://www.icann.org/sites/default/files/lgr/lgr-4-common-29jun20-en.xml
non-normative HTML presentation:
https://www.icann.org/sites/default/files/lgr/lgr-4-common-29jun20-en.html
[RZ-LGR-4-Overview]
Integration Panel, "Root Zone Label Generation Rules - LGR-4: Overview and Summary", 29 June 2020 (PDF),
https://www.icann.org/sites/default/files/lgr/lgr-4-overview-29jun20-en.pdf
[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 Bengali script for the Root Zone please see details in the Table of References below. References [0] and [7] refer to the Unicode Standard versions in which the corresponding code points were initially encoded. References [101] and above correspond to sources given in [Proposal-Bengali] justifying the inclusion of the corresponding code points. Entries in the table may have multiple source reference values.

2 Repertoire

Repertoire Summary

Number of elements in Repertoire 70
Out of repertoire variants 4
Total entries in table 74
Number of code points
for each script
Bengali 61
Devanagari 2
Gurmukhi 2
Number of code points 65
Number of sequences 9
Longest code point sequence 4
Code points defined via 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.

Some code points that may be part of a valid label under this LGR only occur as part of one or more sequences. Such code points are not listed individually in the table.

For any code point or sequence for which a variant is defined, additional information is provided in the Variants column. Some code points or sequences listed in the following table are not part of the repertoire itself; they document targets for out-of-repertoire variant mappings as indicated. See also the legend provided below the table.

Code
Point
Glyph Script Name Ref Tags Required Context Part of
Repertoire
Variants Comment
U+092E Devanagari DEVANAGARI LETTER MA [0]     set 1 Not part of repertoire
U+093F ि Devanagari DEVANAGARI VOWEL SIGN I [0]     set 2 Not part of repertoire
U+0981 Bengali BENGALI SIGN CANDRABINDU [0], [101], [102], [103] Candrabindu follows-only-V-C-M   Bangla, Manipuri, Assamese
U+0982 Bengali BENGALI SIGN ANUSVARA [0], [101], [102], [103] Anusvara follows-only-V-C-M-D   Bangla, Manipuri, Assamese
U+0983 Bengali BENGALI SIGN VISARGA [0], [101], [102], [103] Visarga follows-only-V-C-M-D   Bangla, Manipuri, Assamese
U+0985 Bengali BENGALI LETTER A [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0985 U+09CD U+09AF U+09BE অ্যা {Bengali} BENGALI LETTER A + BENGALI SIGN VIRAMA + BENGALI LETTER YA + BENGALI VOWEL SIGN AA   [Vowel] + [Halant] + [Consonant] + [Matra] not: follows-H   Ya-Phalaa (s1): Bangla, Assamese
U+0986 Bengali BENGALI LETTER AA [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0987 Bengali BENGALI LETTER I [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0988 Bengali BENGALI LETTER II [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0989 Bengali BENGALI LETTER U [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+098A Bengali BENGALI LETTER UU [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+098B Bengali BENGALI LETTER VOCALIC R [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+098F Bengali BENGALI LETTER E [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+098F U+09CD U+09AF U+09BE এ্যা {Bengali} BENGALI LETTER E + BENGALI SIGN VIRAMA + BENGALI LETTER YA + BENGALI VOWEL SIGN AA   [Vowel] + [Halant] + [Consonant] + [Matra] not: follows-H   Ya-Phalaa (s2): Bangla
U+0990 Bengali BENGALI LETTER AI [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0993 Bengali BENGALI LETTER O [0], [101], [102], [103] Vowel not: follows-H   Bangla, Manipuri, Assamese
U+0994 Bengali BENGALI LETTER AU [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+0995 Bengali BENGALI LETTER KA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+0996 Bengali BENGALI LETTER KHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+0997 Bengali BENGALI LETTER GA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+0998 Bengali BENGALI LETTER GHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+0999 Bengali BENGALI LETTER NGA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099A Bengali BENGALI LETTER CA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099B Bengali BENGALI LETTER CHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099C Bengali BENGALI LETTER JA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099D Bengali BENGALI LETTER JHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099E Bengali BENGALI LETTER NYA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+099F Bengali BENGALI LETTER TTA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A0 Bengali BENGALI LETTER TTHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A1 Bengali BENGALI LETTER DDA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A1 U+09BC ড় {Bengali} BENGALI LETTER DDA + BENGALI SIGN NUKTA [0], [101], [102], [103] [Consonant] + []     09DC is the preferred code point, however it is not available for LGR as per the standards governing this LGR development
U+09A2 Bengali BENGALI LETTER DDHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese,
U+09A2 U+09BC ঢ় {Bengali} BENGALI LETTER DDHA + BENGALI SIGN NUKTA [0], [101], [102], [103] [Consonant] + []     09DD is the preferred code point, however it is not available for LGR as per the standards governing this LGR development
U+09A3 Bengali BENGALI LETTER NNA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A4 Bengali BENGALI LETTER TA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A5 Bengali BENGALI LETTER THA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A6 Bengali BENGALI LETTER DA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A7 Bengali BENGALI LETTER DHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A8 Bengali BENGALI LETTER NA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09A8 U+09CD U+09A5 ন্থ {Bengali} BENGALI LETTER NA + BENGALI SIGN VIRAMA + BENGALI LETTER THA   [Consonant] + [Halant] + [Consonant]   set 3 Bengali variant
U+09A8 U+09CD U+09B9 ন্হ {Bengali} BENGALI LETTER NA + BENGALI SIGN VIRAMA + BENGALI LETTER HA   [Consonant] + [Halant] + [Consonant]   set 3 Bengali variant
U+09AA Bengali BENGALI LETTER PA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09AB Bengali BENGALI LETTER PHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09AC Bengali BENGALI LETTER BA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09AD Bengali BENGALI LETTER BHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09AE Bengali BENGALI LETTER MA [0], [101], [102], [103] Consonant   set 1 Bangla, Manipuri, Assamese
U+09AF Bengali BENGALI LETTER YA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09AF U+09BC য় {Bengali} BENGALI LETTER YA + BENGALI SIGN NUKTA [0], [101], [102], [103] [Consonant] + []     09DF is the preferred code point, however it is not available for LGR as per the standards governing this LGR development
U+09B0 Bengali BENGALI LETTER RA [0], [101], [102] C2, Consonant   set 4 Bangla, Manipuri
U+09B2 Bengali BENGALI LETTER LA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09B6 Bengali BENGALI LETTER SHA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09B7 Bengali BENGALI LETTER SSA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09B8 Bengali BENGALI LETTER SA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09B8 U+09CD U+09A5 স্থ {Bengali} BENGALI LETTER SA + BENGALI SIGN VIRAMA + BENGALI LETTER THA   [Consonant] + [Halant] + [Consonant]   set 5 Bengali variant
U+09B8 U+09CD U+09B9 স্হ {Bengali} BENGALI LETTER SA + BENGALI SIGN VIRAMA + BENGALI LETTER HA   [Consonant] + [Halant] + [Consonant]   set 5 Bengali variant
U+09B9 Bengali BENGALI LETTER HA [0], [101], [102], [103] Consonant     Bangla, Manipuri, Assamese
U+09BE Bengali BENGALI VOWEL SIGN AA [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09BF ি Bengali BENGALI VOWEL SIGN I [0], [101], [102], [103] Matra follows-only-C set 2 Bangla, Manipuri, Assamese
U+09C0 Bengali BENGALI VOWEL SIGN II [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09C1 Bengali BENGALI VOWEL SIGN U [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09C2 Bengali BENGALI VOWEL SIGN UU [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09C3 Bengali BENGALI VOWEL SIGN VOCALIC R [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09C4 Bengali BENGALI VOWEL SIGN VOCALIC RR [0], [101], [103] Matra follows-only-C   Bangla, Assamese
U+09C7 Bengali BENGALI VOWEL SIGN E [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09C8 Bengali BENGALI VOWEL SIGN AI [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09CB Bengali BENGALI VOWEL SIGN O [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09CC Bengali BENGALI VOWEL SIGN AU [0], [101], [102], [103] Matra follows-only-C   Bangla, Manipuri, Assamese
U+09CD Bengali BENGALI SIGN VIRAMA [0], [101], [102], [103] Halant follows-only-C   Bangla, Manipuri, Assamese
U+09CE Bengali BENGALI LETTER KHANDA TA [7], [101], [102], [103] Consonant, KhandaTa follows-only-V-C-M-D-B-X-P   Bangla, Manipuri, Assamese
U+09F0 Bengali BENGALI LETTER RA WITH MIDDLE DIAGONAL [0], [103] C2, Consonant   set 4 Assamese
U+09F1 Bengali BENGALI LETTER RA WITH LOWER DIAGONAL [0], [102], [103] Consonant     Manipuri, Assamese
U+0A38 Gurmukhi GURMUKHI LETTER SA [0]     set 1 Not part of repertoire
U+0A3F ਿ Gurmukhi GURMUKHI VOWEL SIGN I [0]     set 2 Not part of repertoire

Legend

Throughout this LGR, a code point sequence may be annotated with a string in ALL CAPS that is constructed on the same principle as a name for a Unicode Named Sequence. No claim is made that a sequence thus annotated is in fact a named sequence, nor that the annotation in such case actually corresponds to the formal name of a named sequence.

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. Sequences are annotated with a set of all distinct script values.
Name
Shows the character or sequence name from the Unicode Character Database. Named sequences are listed with their normative names, for ad-hoc sequences the individual names are shown separated by “+”.
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. For sequences, the tags for all member code points are shown for information; sequences as such do not have tags.
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.
✔ - core repertoire
A check mark in the Part-of-Repertoire column indicates a code point is part of the core repertoire.
✗ - out-of-repertoire
A code point shown with is not part of the repertoire. It is listed only because it is the target of an out-of-repertoire-var variant mapping.

3 Variant Sets

Variant Set Summary

Number of variant sets 5
Largest variant set 3
Ordinary Variants by Type
allocatable 2
blocked 16
Reflexive Variants by Type
out-of-repertoire-var 4

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.

A mapping where source and target are the same is reflexive. Variant sets consisting of only a single reflexive mapping are not shown as a set. Instead, the variant type of the mapping is listed in the Variants column of the Repertoire by Code Point table. Reflexive mappings that are part of a larger set are indicated with a “≡” and are counted once per entry.

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.
- reflexive
Indicates that Type, Ref and Comment are for a reflexive mapping where source equals target.
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. A reflexive variant type “out-of-repertoire-var” designates the target as not part of the repertoire; it is required as target for one or more variant mappings that cross repertoire boundaries.
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 — 3 Members

Source Glyph Target Glyph   Type Ref Comment
092E 092E out-of-repertoire-var   Out-of-repertoire
092E 09AE blocked   Cross-script homoglyph
092E 0A38 blocked   Cross-script homoglyph
09AE 0A38 blocked   Cross-script homoglyph
0A38 0A38 out-of-repertoire-var   Out-of-repertoire

Variant Set 2 — 3 Members

Source Glyph Target Glyph   Type Ref Comment
093F ि 093F ि out-of-repertoire-var   Out-of-repertoire
093F ि 09BF ি blocked   Cross-script homoglyph
093F ि 0A3F ਿ blocked   Cross-script homoglyph
09BF ি 0A3F ਿ blocked   Cross-script homoglyph
0A3F ਿ 0A3F ਿ out-of-repertoire-var   Out-of-repertoire

Variant Set 3 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
09A8 09CD 09A5 ন্থ 09A8 09CD 09B9 ন্হ blocked   Bengali variant

Variant Set 4 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
09B0 09F0 allocatable   Bengali variant

Variant Set 5 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
09B8 09CD 09A5 স্থ 09B8 09CD 09B9 স্হ blocked   Bengali 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-single Tag=Consonant 36 {0994-09A8 09AA-09B0 09B2 09B6-09B9 09CE 09F0-09F1}    
V Tag=Vowel 10 {0985-098B 098F-0990 0993}    
M Tag=Matra 11 {09BE-09C4 09C7-09C8 09CB-09CC}    
H Tag=Halant 1 {09CD}    
B Tag=Anusvara 1 {0982}    
X Tag=Visarga 1 {0983}    
D Tag=Candrabindu 1 {0981}    
C2 Tag=C2 2 {09B0 09F0}    
implicit Tag=KhandaTa 1 {09CE}   The character tagged as KhandaTa
implicit Tag=sc:Beng 61 {0981-0983 0985-098B 098F-0990 0993-09A8 09AA-09B0 09B2 09B6-09B9 09BE-09C4 09C7-09C8 09CB-09CE 09F0-09F1}   Any character tagged as Bengali
implicit Tag=sc:Deva 2 {092E 093F}   Any character tagged as Devanagari
implicit Tag=sc:Guru 2 {0A38 0A3F}   Any character tagged as Gurmukhi

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
C-RRA \u09A1\u09BC         NFC form of BENGALI LETTER RRA
C-RHA \u09A2\u09BC         NFC form of BENGALI LETTER RHA
C-YYA \u09AF\u09BC         NFC form of BENGALI LETTER YYA
C [:C-single:]|(:C-RRA:)|(:C-RHA:)|(:C-YYA:)         Section 7, WLE1: All consonants in the LGR repertoire; single code points and sequences
leading-combining-mark (start)[[\p{gc=Mn}] ∪ [\p{gc=Mc}]]       Default WLE rule matching labels with leading combining marks ⍟
follows-only-C ((:C:))← ⚓   C   Section 7, WLE 2: H: must be preceded by C ; WLE 3: M: must be preceded by C
follows-only-V-C-M ([:V:]|(:C:)|[:M:])← ⚓   C   Section 7, WLE 4: D: must be preceded by any of V, C, M
follows-only-V-C-M-D ([:V:]|(:C:)|[:M:]|[:D:])← ⚓   C   Section 7, WLE 5: X: must be preceded by any of V, C, M, D; WLE 6: B: must be preceded by any of V, C, M, D
P [:C2:][:H:]         Ra-Hasanta, defined for use in WLE-7
follows-only-V-C-M-D-B-X-P ([:V:]|(:C:)|[:M:]|[:D:]|[:B:]|[:X:]|(:P:))← ⚓   C   Section 7, WLE 7: Khanda Ta must be preceded by V, C, M, D, B, X, P
follows-H ([:H:])← ⚓   C   Section 7, WLE 8: V cannot be preceded by H, WLE 9: S cannot be preceded by H
no-mix-09B0-09F0 (\u09B0.*\u09F0)|(\u09F0.*\u09B0)       Section 7, WLE 10: U+09B0 (র) and U+09F0 (ৰ) cannot be mixed.

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.
(: :) - rule reference
Non-recursive reference to a named rule.
(... | ...) - 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   labels with leading combining marks are invalid ⍟
2 if label matches no-mix-09B0-09F0 invalid   WLE 10: U+09B0 and U+09F0 cannot be mixed.
3 if at least one variant is in {out-of-repertoire-var} invalid   any variant label with a code point Not part of repertoire is invalid ⍟
4 if at least one variant is in {blocked} blocked   default action MSR-4 ⍟
5 if at least one variant is in {allocatable} allocatable   default action MSR-4 ⍟
6 if any label (catch-all)   valid   catch all; default action from MSR-4 ⍟

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
[7] The Unicode Standard 4.1
Any code point originally encoded in Unicode 4.1
[101] Wikipedia, Bengali alphabet, accessed on 2017-11-25
https://en.wikipedia.org/wiki/Bengali_alphabet
[102] Bengali alphabet for Manipuri, found in Omniglot, Manipuri (Meeteilon/ Meithei), accessed on 20.10.2019
https://www.omniglot.com/writing/manipuri.htm
[103] Omniglot, Assamese (অসমীয়া), accessed on 2020-04-28
https://www.omniglot.com/writing/assamese.htm