Reference LGR for script: Malayalam (Mlym) lgr-second-level-malayalam-script-24aug20-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 2020-08-24
LGR Version 3
Language und-Mlym
Unicode Version 6.3.0

Table of Contents

1 Description

Reference Label Generation Rules for the Malayalam script


This document specifies a reference set of Label Generation Rules (LGR) for the Malayalam 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-3-Mlym]. For details and additional background on the script, see "Proposal for a Malayalam Script Root Zone Label Generation Ruleset (LGR) [Proposal-Malayalam]". 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 the Second Level Reference LGRs for details on how to submit comments.


The repertoire contains 70 code points for letters used in the Malayalam language in addition to ten sequences used in defining variants. The repertoire is a subset of [Unicode 6.3]. For more detail, see Section 5, "Repertoire" in [Proposal-Malayalam]. (The proposal cited has been adopted for the Malayalam script portion of the Root Zone LGR.)

For the second level, the repertoire has been augmented with the ASCII digits, U+0030 (0) to U+0039 (9), and U+002D (-) HYPHEN-MINUS for a total of 91 repertoire elements.

Code points outside the Malayalam 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.

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.


This reference LGR is designed for use in zones shared by more than one script. Where appropriate, cross-script variants have been defined to mutually exclude labels from different scripts that could otherwise be substituted by the users. Once a label has been delegated for one script, any variant labels from other scripts consisting of cross-script variants would be blocked. Any label containing at least one code point that is not a cross-script variant would be considered distinct. Because of that, even large numbers of defined cross-script variants generally do not lead to a high percentage of labels experiencing a collision.

This LGR defines in-script variants and cross-script variants as described in Section 6, "Variants", in "[Proposal-Malayalam]". One in-script variant is due to the multiple ways to write the conjunct “nta" in Malayalam. Cross-script variants are mainly defined for Tamil code points.

Digit Variants: The Malayalam reference LGR does not include native digits, so there are no variants defined. By transitivity, all ASCII digits are semantic variants of any cross-script native digits. Any Malayalam label that is otherwise a cross-script variant of a label in another script, will remain a variant if both labels add digits of the same value in the same position, irrespective of whether they are ASCII or (in the case of the other script) native digits. However, some Malayalam letters are homoglyphs of Malayalam native digits. For example, U+0D6A (൪) MALAYALAM DIGIT FOUR and U+0D6F (൯) MALAYALAM DIGIT NINE are homoglyphs of U+0D7C (ർ) MALAYALAM CHILLU RR and U+0D7D (ൽ) MALAYALAM CHILLU N respectively. Should an extension be contemplated that adds native digits, these might require variant relations. At the same time, however, the native digits would normally also be semantic variants of the European digits. In any zone containing multiple scripts, these two types of variant relation for digits may lead to complication once transitivity is applied.

Variant Disposition: All 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 this reference LGR follows the guidelines in [RFC 8228].

Context Rules for Variants: some of the variants defined in this LGR are "effective null variants", that is, some code points in the source map to "nothing" in the target with all other code points unchanged. (Because mappings are symmetric, it does not matter whether it is the forward or reverse mapping that maps to "null"). Such variants require a context rule to keep the variant set well-behaved. Symmetry requires the same context rule for both forward and reverse mappings.

In other cases, the sequences or code points making up source and target are constrained by context rules on the code points. In such a case, any variants require context rules that match the intersection between the contexts for both source and target; otherwise a sequence might be considered valid in some variant label when it would not be valid in an equivalent context in an original label.

Character Classes

The basic characters in Malayalam are classified here into the following categories: Consonants, Vowels, Matra and Reordrant Vowel Diacritics, Halant, Visargam, Anusvaram and Chillu letters.

Consonant: Malayalam is written in an abugida script derived ultimately from Brahmi in which every consonant carries an inherent /a/. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Vowels: Like consonants, the independent vowels can follow any other class of code points in a label.

Matra: Vowels other than the inherent vowel are written as vowel diacritics. They are referred to as Matras, when they follow consonants. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Halant: A consonant can be combined with another consonant or conjunct using the halant encoded as U+0D4D (്) MALAYALAM SIGN VIRAMA. This strips off the implicit vowel. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Anusvaram: In Malayalam, anusvara represented as U+0D02 (ം), simply represents a consonant /m/ after a vowel, though this /m/ may be assimilated to another nasal consonant. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Visargam: The visarga represents a consonant /h/ after a vowel, and is transliterated as ḥ. Like the anusvara, it is a special symbol, and is never followed by an inherent vowel or another vowel. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Chillu: Chillu letters, aka "Chillaksharam", represent pure consonants without any vowel sound. More details in Section 3.8, "The Structure of Malayalam Script" of [Proposal-Malayalam].

Reordrant: Vowel diacritics, part of which reorder around the preceding character or conjunct. More details in Sections 6.1 "In-script Variants" and 7.1.1 "Variables or definitions" of [Proposal-Malayalam].

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].

Malayalam-specific Rules

There are constraints on the context for many of the character classes in Malayalam. A corresponding set of context and whole label rules has been formulated for LGR specification, as described in Section 7, "Whole Label Evaluation (WLE) Rules" in [Proposal-Malayalam].

The following symbols are used in the WLE rules:
C → Consonant
M → Matra
V → Vowel
B → Anusvara
X → Visarga
D → Chandrabindu
H → Halant
L → Chillu
R → Reordrant Matra

Note: the Reordrant Matras include one sequence. That requires an auxiliary rule R in addition to class R.

The rules are:

The following context rules apply to Consonants U+0D33 (ള) RRA and U+0D31 (റ) LLA as well as to sequences ending in these code points:

Note: the implementation of Rules 7 & 8 relies on the fact that a context rule is not evaluated between code points in the same sequence. For example, if a label contains two adjacent U+0D33 U+0D33 (ളള) surrounded by other code points , the two code points can only be interpreted as the sequence U+0D33 U+0D33 (ളള) because a singleton U+0D33 (ള) is not allowed to be followed by another U+0D33 (ള).

The following context rule applies to the sequence Chillu N + Halant (U+0D7B U+0D4D):

The following context rules apply to variants:

These rules ensure that the variant label sets are well-behaved in cases where variant sequences overlap.

Note: any sequences ending with 0D31 would overlap with the various variant sequences beginning with 0D31, therefore this LGR drops the 0D31 from the end of these sequences, but adds context rule V1, when="followed-by-0D31" instead. Because all the variants also end in 0D31, this results in the same generated variants as if the sequences had been defined with trailing U+0D31 (റ), but now the variants are well-behaved in all contexts.

More details in Section 6.1, "In-script Variants" and Section 7, "Whole Label Evaluation Rules (WLE)" of [Proposal-Malayalam].

There are a number of cross-script homoglyphs to U+0D31 (റ) RRA, which would interact with the definition of in-script sequences and variants, leading to unacceptable complexity. These variants would affect only labels made solely of letters RRA, and no other labels. Rule 8 already restricts labels consisting solely of copies of the letter RRA to either "റ" or "ററ", thus allowing only two such labels. The following rule disallows the remaining two possible labels, obviating any need to define these cross-script variants.

Malayalam-specific actions

WLE rules 6 and 10 trigger Malayalam-specific actions to invalidate any original and variant labels not satisfying the constraints. See Section 7, "Whole Label Evaluation (WLE) Rules" in [Proposal-Malayalam].

Methodology and Contributors

This reference LGR for Malayalam for the 2nd Level has been developed by Michel Suignard and Asmus Freytag, based on the latest available Root Zone LGR for Malayalam and information contained or referenced therein, see [RZ-LGR-3-Mlym]. Suitable extensions for the second level have been applied according to the [Guidelines]. The original proposal for a Root Zone LGR for the Malayalam 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 [Proposal-Malayalam].


The following general references are cited in this document:

ICANN, "Guidelines for Developing Reference LGRs for the Second Level, (Los Angeles, California: ICANN, 27 May 2020),
Neo-Brahmi Generation Panel, "Proposal for a Malayalam Script Root Zone Label Generation Ruleset (LGR)", 7 May 2020,
[RFC 7940]
Davies, K. and A. Freytag, "Representing Label Generation Rulesets Using XML", RFC 7940, August 2016,
[RFC 8228]
A. Freytag, "Guidance on Designing Label Generation Rulesets (LGRs) Supporting Variant Labels", RFC 8228, August 2017,
ICANN, Root Zone Label Generation Rules for the Malayalam Script (und-Mlym) , 10 July 2019 (XML)
Integration Panel, "Root Zone Label Generation Rules - LGR-3: Overview and Summary", 01 March 2020 (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)

For references consulted particularly in designing the repertoire for the Malayalam script for the Root Zone please see details in the Table of References below. References [0] to [9] refer to the Unicode Standard versions in which the corresponding code points were initially encoded. Reference [106] corresponds to a source given in [Proposal-Malayalam] 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 91
Out of repertoire variants 7
Total entries in table 98
Number of code points
for each script
Malayalam 70
Oriya 1
Tamil 6
Common 11
Number of code points 88
Number of sequences 10
Longest code point sequence 4

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. 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.

Glyph Script Name Ref Tags Required Context Part of
Variants Comment
U+002D - Common HYPHEN-MINUS [0] Hyphen not: hyphen-minus-disallowed  
U+0030 0 Common DIGIT ZERO [0] Common-digit    
U+0031 1 Common DIGIT ONE [0] Common-digit    
U+0032 2 Common DIGIT TWO [0] Common-digit    
U+0033 3 Common DIGIT THREE [0] Common-digit    
U+0034 4 Common DIGIT FOUR [0] Common-digit    
U+0035 5 Common DIGIT FIVE [0] Common-digit    
U+0036 6 Common DIGIT SIX [0] Common-digit    
U+0037 7 Common DIGIT SEVEN [0] Common-digit    
U+0038 8 Common DIGIT EIGHT [0] Common-digit    
U+0039 9 Common DIGIT NINE [0] Common-digit    
U+0B20 Oriya ORIYA LETTER TTHA [0]     set 1 not part of repertoire
U+0B9C Tamil TAMIL LETTER JA [0]     set 2 not part of repertoire
U+0BAE Tamil TAMIL LETTER MA [0]     set 3 not part of repertoire
U+0BB5 Tamil TAMIL LETTER VA [0]     set 4 not part of repertoire
U+0BBF ி Tamil TAMIL VOWEL SIGN I [0]     set 5 not part of repertoire
U+0BC6 Tamil TAMIL VOWEL SIGN E [0]     set 6 not part of repertoire
U+0BC7 Tamil TAMIL VOWEL SIGN EE [0]     set 7 not part of repertoire
U+0D02 Malayalam MALAYALAM SIGN ANUSVARA [0], [106] Anusvaram follows-C-V-or-M    
U+0D03 Malayalam MALAYALAM SIGN VISARGA [0], [106] Visargam follows-C-V-or-M    
U+0D05 Malayalam MALAYALAM LETTER A [0], [106] Vowel      
U+0D06 Malayalam MALAYALAM LETTER AA [0], [106] Vowel      
U+0D07 Malayalam MALAYALAM LETTER I [0], [106] Vowel      
U+0D08 Malayalam MALAYALAM LETTER II [0], [106] Vowel      
U+0D09 Malayalam MALAYALAM LETTER U [0], [106] Vowel      
U+0D0A Malayalam MALAYALAM LETTER UU [0], [106] Vowel      
U+0D0B Malayalam MALAYALAM LETTER VOCALIC R [0], [106] Vowel      
U+0D0E Malayalam MALAYALAM LETTER E [0], [106] Vowel      
U+0D0F Malayalam MALAYALAM LETTER EE [0], [106] Vowel      
U+0D10 Malayalam MALAYALAM LETTER AI [0], [106] Vowel      
U+0D12 Malayalam MALAYALAM LETTER O [0], [106] Vowel      
U+0D13 Malayalam MALAYALAM LETTER OO [0], [106] Vowel      
U+0D14 Malayalam MALAYALAM LETTER AU [0], [106] Vowel      
U+0D15 Malayalam MALAYALAM LETTER KA [0], [106] Consonant      
U+0D16 Malayalam MALAYALAM LETTER KHA [0], [106] Consonant   set 4  
U+0D17 Malayalam MALAYALAM LETTER GA [0], [106] Consonant      
U+0D18 Malayalam MALAYALAM LETTER GHA [0], [106] Consonant      
U+0D19 Malayalam MALAYALAM LETTER NGA [0], [106] Consonant      
U+0D1A Malayalam MALAYALAM LETTER CA [0], [106] Consonant      
U+0D1B Malayalam MALAYALAM LETTER CHA [0], [106] Consonant      
U+0D1C Malayalam MALAYALAM LETTER JA [0], [106] Consonant   set 2  
U+0D1D Malayalam MALAYALAM LETTER JHA [0], [106] Consonant      
U+0D1E Malayalam MALAYALAM LETTER NYA [0], [106] Consonant      
U+0D1F Malayalam MALAYALAM LETTER TTA [0], [106] Consonant      
U+0D20 Malayalam MALAYALAM LETTER TTHA [0], [106] Consonant   set 1  
U+0D21 Malayalam MALAYALAM LETTER DDA [0], [106] Consonant      
U+0D22 Malayalam MALAYALAM LETTER DDHA [0], [106] Consonant      
U+0D23 Malayalam MALAYALAM LETTER NNA [0], [106] Consonant      
U+0D24 Malayalam MALAYALAM LETTER TA [0], [106] Consonant      
U+0D25 Malayalam MALAYALAM LETTER THA [0], [106] Consonant   set 3  
U+0D26 Malayalam MALAYALAM LETTER DA [0], [106] Consonant      
U+0D27 Malayalam MALAYALAM LETTER DHA [0], [106] Consonant      
U+0D28 Malayalam MALAYALAM LETTER NA [0], [106] Consonant      
U+0D28 U+0D4D ന് {Malayalam} MALAYALAM LETTER NA + MALAYALAM SIGN VIRAMA [0], [106] [Consonant] + [Halant] not: follows-B-X-or-H set 8  
U+0D2A Malayalam MALAYALAM LETTER PA [0], [106] Consonant      
U+0D2B Malayalam MALAYALAM LETTER PHA [0], [106] Consonant      
U+0D2C Malayalam MALAYALAM LETTER BA [0], [106] Consonant      
U+0D2D Malayalam MALAYALAM LETTER BHA [0], [106] Consonant      
U+0D2E Malayalam MALAYALAM LETTER MA [0], [106] Consonant      
U+0D2F Malayalam MALAYALAM LETTER YA [0], [106] Consonant      
U+0D30 Malayalam MALAYALAM LETTER RA [0], [106] Consonant      
U+0D31 Malayalam MALAYALAM LETTER RRA [0], [106] Consonant not: follows-0D31    
U+0D31 U+0D31 ററ {Malayalam} MALAYALAM LETTER RRA + MALAYALAM LETTER RRA   [Consonant] + [Consonant] not: follows-0D31 set 9  
U+0D31 U+0D31 U+0D4D U+0D31 ററ്റ {Malayalam} MALAYALAM LETTER RRA + MALAYALAM LETTER RRA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER RRA   [Consonant] + [Consonant] + [Halant] + [Consonant] not: follows-0D31 set 10  
U+0D31 U+0D4D U+0D31 റ്റ {Malayalam} MALAYALAM LETTER RRA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER RRA   [Consonant] + [Halant] + [Consonant] not: follows-0D31 set 9  
U+0D31 U+0D4D U+0D31 U+0D31 റ്ററ {Malayalam} MALAYALAM LETTER RRA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER RRA + MALAYALAM LETTER RRA   [Consonant] + [Halant] + [Consonant] + [Consonant] not: follows-0D31 set 10  
U+0D32 Malayalam MALAYALAM LETTER LA [0], [106] Consonant      
U+0D33 Malayalam MALAYALAM LETTER LLA [0], [106] Consonant not: follows-0D33    
U+0D33 U+0D33 ളള {Malayalam} MALAYALAM LETTER LLA + MALAYALAM LETTER LLA   [Consonant] + [Consonant] not: follows-0D33 set 11  
U+0D33 U+0D33 U+0D4D U+0D33 ളള്ള {Malayalam} MALAYALAM LETTER LLA + MALAYALAM LETTER LLA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER LLA   [Consonant] + [Consonant] + [Halant] + [Consonant] not: follows-0D33 set 12  
U+0D33 U+0D4D U+0D33 ള്ള {Malayalam} MALAYALAM LETTER LLA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER LLA   [Consonant] + [Halant] + [Consonant] not: follows-0D33 set 11  
U+0D33 U+0D4D U+0D33 U+0D33 ള്ളള {Malayalam} MALAYALAM LETTER LLA + MALAYALAM SIGN VIRAMA + MALAYALAM LETTER LLA + MALAYALAM LETTER LLA   [Consonant] + [Halant] + [Consonant] + [Consonant] not: follows-0D33 set 12  
U+0D34 Malayalam MALAYALAM LETTER LLLA [0], [106] Consonant      
U+0D35 Malayalam MALAYALAM LETTER VA [0], [106] Consonant      
U+0D36 Malayalam MALAYALAM LETTER SHA [0], [106] Consonant      
U+0D37 Malayalam MALAYALAM LETTER SSA [0], [106] Consonant      
U+0D38 Malayalam MALAYALAM LETTER SA [0], [106] Consonant      
U+0D39 Malayalam MALAYALAM LETTER HA [0], [106] Consonant      
U+0D3E Malayalam MALAYALAM VOWEL SIGN AA [0], [106] Matra follows-C    
U+0D3F ി Malayalam MALAYALAM VOWEL SIGN I [0], [106] Matra follows-C set 5  
U+0D40 Malayalam MALAYALAM VOWEL SIGN II [0], [106] Matra follows-C    
U+0D41 Malayalam MALAYALAM VOWEL SIGN U [0], [106] Matra follows-C    
U+0D42 Malayalam MALAYALAM VOWEL SIGN UU [0], [106] Matra follows-C    
U+0D43 Malayalam MALAYALAM VOWEL SIGN VOCALIC R [0], [106] Matra follows-C    
U+0D46 Malayalam MALAYALAM VOWEL SIGN E [0], [106] Matra, R follows-C set 6  
U+0D47 Malayalam MALAYALAM VOWEL SIGN EE [0], [106] Matra, R follows-C set 7  
U+0D48 Malayalam MALAYALAM VOWEL SIGN AI [0], [106] Matra, R follows-C    
U+0D4A Malayalam MALAYALAM VOWEL SIGN O [0], [106] Matra, R follows-C    
U+0D4B Malayalam MALAYALAM VOWEL SIGN OO [0], [106] Matra, R follows-C    
U+0D4D Malayalam MALAYALAM SIGN VIRAMA [0], [106] Halant follows-C-or-0D41    
U+0D57 Malayalam MALAYALAM AU LENGTH MARK [0], [106] Matra follows-C    
U+0D7A Malayalam MALAYALAM LETTER CHILLU NN [9], [106] Chillu not: follows-B-X-or-H    
U+0D7B Malayalam MALAYALAM LETTER CHILLU N [9], [106] Chillu not: follows-B-X-or-H set 8  
U+0D7B U+0D4D ൻ് {Malayalam} MALAYALAM LETTER CHILLU N + MALAYALAM SIGN VIRAMA   [Chillu] + [Halant] follows-C-L-M-V-and-followed-by-03D1 set 8  
U+0D7C Malayalam MALAYALAM LETTER CHILLU RR [9], [106] Chillu not: follows-B-X-or-H    
U+0D7D Malayalam MALAYALAM LETTER CHILLU L [9], [106] Chillu not: follows-B-X-or-H    
U+0D7E Malayalam MALAYALAM LETTER CHILLU LL [9], [106] Chillu not: follows-B-X-or-H    
U+0D7F ൿ Malayalam MALAYALAM LETTER CHILLU K [9], [106] Chillu not: follows-B-X-or-H    


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.
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. Sequences are annotated with a set of all distinct script values.
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 “+”.
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. 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.
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.
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.
✔ - 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 12
Largest variant set 3
Ordinary Variants by Type
blocked 28
Reflexive Variants by Type
out-of-repertoire-var 7

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 variant sets for each context are disjoint, but code points that have variants with multiple contexts are members of more than one set.

Common Legend

By convention, the smaller of the two code points in a variant mapping pair.
By convention, the larger of the two code points in a variant mapping pair.
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.
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.
Required Context
Link to the rule defining a required context the source must satisfy for the variant mapping to be defined. If prefixed by “not:”, identifies a context that must not occur.
One or more reference IDs (optional). A “/” separates references for reverse / forward mappings, if different.
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
0B20 0B20 out-of-repertoire-var   Out of repertoire
0B20 0D20 blocked   Cross-script homoglyph

Variant Set 2 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0B9C 0B9C out-of-repertoire-var   Out of repertoire
0B9C 0D1C blocked   Cross-script homoglyph

Variant Set 3 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0BAE 0BAE out-of-repertoire-var   Out of repertoire
0BAE 0D25 blocked   Cross-script homoglyph

Variant Set 4 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0BB5 0BB5 out-of-repertoire-var   Out of repertoire
0BB5 0D16 blocked   Cross-script homoglyph

Variant Set 5 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0BBF ி 0BBF ி out-of-repertoire-var   Out of repertoire
0BBF ி 0D3F ി blocked   Cross-script homoglyph

Variant Set 6 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0BC6 0BC6 out-of-repertoire-var   Out of repertoire
0BC6 0D46 blocked   Cross-script homoglyph

Variant Set 7 — 2 Members

Source Glyph Target Glyph   Type Ref Comment
0BC7 0BC7 out-of-repertoire-var   Out of repertoire
0BC7 0D47 blocked   Cross-script homoglyph

Variant Set 8 — 3 Members

Source Glyph Target Glyph   Type Required Context Ref Comment
0D28 0D4D ന് 0D7B blocked followed-by-0D31    
0D28 0D4D ന് 0D7B 0D4D ൻ് blocked followed-by-0D31    
0D7B 0D7B 0D4D ൻ് blocked followed-by-0D31    

Variant Set 9 — 2 Members

Source Glyph Target Glyph   Type Required Context Ref Comment
0D31 0D31 ററ 0D31 0D4D 0D31 റ്റ blocked not: follows-0D31-0D4D-or-followed-by-0D4D-0D31-or-R    

Variant Set 10 — 2 Members

Source Glyph Target Glyph   Type Required Context Ref Comment
0D31 0D31 0D4D 0D31 ററ്റ 0D31 0D4D 0D31 0D31 റ്ററ blocked not: followed-by-R    

Variant Set 11 — 2 Members

Source Glyph Target Glyph   Type Required Context Ref Comment
0D33 0D33 ളള 0D33 0D4D 0D33 ള്ള blocked not: follows-0D33-0D4D-or-followed-by-0D4D-0D33-or-R    

Variant Set 12 — 2 Members

Source Glyph Target Glyph   Type Required Context Ref Comment
0D33 0D33 0D4D 0D33 ളള്ള 0D33 0D4D 0D33 0D33 ള്ളള blocked not: followed-by-R    

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 36 {0D15-0D28 0D2A-0D39}   Any Malayalam consonant
V Tag=Vowel 13 {0D05-0D0B 0D0E-0D10 0D12-0D14}   Any Malayalam independent vowel
M Tag=Matra 12 {0D3E-0D43 0D46-0D48 0D4A-0D4B 0D57}   Any Malayalam vowel sign (matra)
H Tag=Halant 1 {0D4D}   The Malayalam Halant/Virama
B Tag=Anusvaram 1 {0D02}   The Malayalam Anusvaram
X Tag=Visargam 1 {0D03}   The Malayalam Visargam
L Tag=Chillu 6 {0D7A-0D7F}   Any Malayalam chillu (consonant without any vowel sound)
R Tag=R 5 {0D46-0D48 0D4A-0D4B}   Any Malayalam reordrant vowel sign
hyphen Tag=Hyphen 1 {002D}   The Hyphen-minus character ⍟
implicit Tag=Common-digit 10 {0030-0039}   Any character tagged as Common-digit
implicit Tag=sc:Mlym 70 {0D02-0D03 0D05-0D0B 0D0E-0D10 0D12-0D28 0D2A-0D39 0D3E-0D43 0D46-0D48 0D4A-0D4B 0D4D 0D57 0D7A-0D7F}   Any character tagged as Malayalam
implicit Tag=sc:Orya 1 {0B20}   Any character tagged as Oriya
implicit Tag=sc:Taml 6 {0B9C 0BAE 0BB5 0BBF 0BC6-0BC7}   Any character tagged as Tamil
implicit Tag=sc:Zyyy 11 {002D 0030-0039}   Any character tagged as Common


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 "...".
A named or implicit class defined by all code points that share the given tag value (ttt).
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
Anchor Used as
Ref Comment
leading-combining-mark (start)[[\p{gc=Mn}] ∪ [\p{gc=Mc}]]       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-C-or-0D41 ([:C:]|\u0D41)← ⚓   C   Section 7, WLE 1: Rule 1: H must be preceded by C or 0D41
follows-C ([:C:])← ⚓   C   Section 7, WLE 2: M must be preceded by C
follows-C-V-or-M ([:C:]|[:V:]|[:M:])← ⚓   C   Section 7, WLE 3: B must be preceded by C, V or M and WLE 4: X must be preceded by C, V or M
follows-B-X-or-H ([:B:]|[:X:]|[:H:])← ⚓   C   Section 7, WLE 5: L cannot be preceded by B, X or H
begins-with-L (start)[:L:]       Section 7, WLE 6: Label does not begin with L
follows-0D33 (\u0D33)← ⚓   C   Section 7, WLE 7. The character ള (0D33) cannot immediately follow ള (0D33), except as part of a defined sequence
follows-0D31 (\u0D31)← ⚓   C   Section 7, WLE 8. The character റ (0D31) cannot immediately follow റ (0D31), except as part of a defined sequence
follows-C-L-M-V-and-followed-by-03D1 ([:C:]|[:L:]|[:M:]|[:V:])← ⚓ →(\u0D31)   C   Section 7, WLE 9: Sequence 0D7B 0D4D must be preceded by C, L, M, V and must be followed by റ (0D31)
reordrant-matra [:R:]|\u0D4D\u0D30         Reordrant matras, including sequence U+0D4D U+0D30 (്ര)
followed-by-R ⚓ →((:reordrant-matra:))   V   variant not defined if followed by reordrant matra
followed-by-0D31 ⚓ →(\u0D31)   V   Section 6.1, V1: A variant is defined when followed by 0D31
follows-0D33-0D4D-or-followed-by-0D4D-0D33-or-R ((\u0D33\u0D4D)← ⚓)|(⚓ →(\u0D4D\u0D33|(:reordrant-matra:)))   V   Section 6.1, V2: variant not defined if preceded by 0D33+Halant or followed by Halant+0D33 or R
follows-0D31-0D4D-or-followed-by-0D4D-0D31-or-R ((\u0D31\u0D4D)← ⚓)|(⚓ →(\u0D4D\u0D31|(:reordrant-matra:)))   V   Section 6.1, V3: variant not defined if preceded by 0D31+Halant or followed by Halant+0D31 or R
only-RRA (start)\u0D31+(end)       Section 7, WLE 10: Labels consisting solely of the letter RRA are disallowed to limit cross-script interaction
ascii-only-label (start)[\u002D\u0030-\u0039]+(end)     [150] RFC 5891 restriction requiring at least one non-ASCII code point ⍟


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.
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.
[ ] - explicit character set
For explicit character sets that are part of a rule, only those members are shown that are defined in this LGR.
[: :] - 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 ascii-only-label invalid [150] ascii-only labels invalid (not IDNs) ⍟
3 if label matches begins-with-L invalid   Section 7, WLE 6: Label does not begin with L
4 if label matches only-RRA invalid   Section 7, WLE 10: Label cannot contain only RRA
5 if at least one variant is in {out-of-repertoire-var} invalid   any variant label with a code point out of repertoire is invalid ⍟
6 if at least one variant is in {blocked} blocked   any variant label containing blocked variants is blocked ⍟
7 if each variant is in {allocatable} allocatable   variant labels with all variants allocatable are allocatable ⍟
8 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.
⍟ - 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
[9] The Unicode Standard 5.1
Any code point originally encoded in Unicode 5.1
[106] Omniglot, "Malayalam (മലയാളം):"
(Accessed on 5th July, 2018)
[150] RFC 5891, Internationalized Domain Names in Applications (IDNA): Protocol