Root Zone Label Generation Rules for the Gujarati Script

Overview

This file contains Label Generation Rules (LGR) for the Gujarati script for the Root Zone. For more details on this LGR and its development, see "Proposal for a Gujarati Script Label Generation Ruleset for the Root Zone" [Proposal]. The format of this file follows [RFC 7940].

Repertoire

According to Section 5, "Repertoire" in [Proposal], the Gujarati LGR contains 65 unique code points. This repertoire covers multiple languages written using the Gujarati script and ranging from 1 to 4 on the [EGIDS] scale.

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

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

Variants

According to Section 6, "Variants", in [Proposal], there are no characters or character sequences in the Gujarati repertoire that look exactly alike. Hence no variants have been defined.

However, Gujarati has some cases of confusingly similar combinations which have been listed in Appendix A in the [Proposal].

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. The writing system of Gujarati could be summed up as composed of Consonants, the Implicit Vowel Killer: Halant, Vowels, Anusvara, Candrabindu, Nukta, Visarga and Avagraha.

Consonants: Gujarati consonants have an implicit schwa /ə/ included in them. As per traditional classification they are categorized according to their phonetic properties. There are 5 Varga groups (classes) and one non-Varga group. Each Varga, which corresponds to Stops, 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].

Halant: All consonants have an implicit vowel sign (schwa) within them. 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 can be generally from 2 to 4 consonant combinations. In rare cases it can join up to 5 consonants. More details in Section 3.4.2, "The Implicit Vowel Killer: Halant" of the [Proposal].

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" of the [Proposal].

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" of the [Proposal].

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. More details in Section 3.4.6, "Nukta" of the [Proposal].

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

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.

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

The rules are:

• 1. N: must be preceded by any of the specific set of Consonants (C1)
• 2. H: must be preceded either by C or N
• 3. X: must be preceded by either of V, C, N or M
• 4. B: must be preceded by either of V, C, N or M
• 5. M: must be preceded either by C or N

More details in Section 7,"Whole Label Evaluation Rules (WLE)" of the [Proposal] /p>

Methodology and Contributors

The LGR for the Gujarati 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 of [Proposal].

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

[EGIDS]

Expanded Graded Intergenerational Disruption Scale,
https://www.ethnologue.com/about/language-status

[Proposal]

NeoBrahmi 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.

[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/

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
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	65	{0A82-0A83 0A85-0A8D 0A8F-0A91 0A93-0AA8 0AAA-0AB0 0AB2-0AB3 0AB5-0AB9 0ABC 0ABE-0AC5 0AC7-0AC9 0ACB-0ACD}		Any character tagged as Gujarati

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}]]	✔				Default WLE rule matching labels with leading combining marks ⍟
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

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 at least one variant is in	{out-of-repertoire-var}	→	invalid		any variant label with a code point out of repertoire is invalid ⍟
3	if at least one variant is in	{blocked}	→	blocked		any variant label containing blocked variants is blocked ⍟
4	if each variant is in	{allocatable}	→	allocatable		variant labels with all variants allocatable are allocatable ⍟
5	if any label (catch-all)		→	valid		catch all (default action) ⍟