Reference Label Generation Rules for the Oriya Script

Overview

This document specifies a reference set of Label Generation Rules (LGR) for the Oriya (Odia) 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-Orya]. For details and additional background on the script, see "Proposal for an Oriya Script Root Zone Label Generation Ruleset (LGR)" [Proposal-Oriya]. The format of this file follows [RFC 7940].

While Oriya is the name under which the script is encoded in Unicode, and is therefore used here to formally identify the script, the name Odia has become the preferred name in English for both script and language as it is closer to the pronunciation of their native names.

Repertoire

The repertoire contains 62 code points for letters, covering the Oriya (Odia) language as well as all other languages written with the Oriya 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-Oriya]. (The proposal cited has been adopted for the Oriya 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 73 repertoire elements.

Code points outside the Oriya 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. Comments provide alternate names of some code points.

Variants

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 one set of cross script variants with the Malayalam script, two sets of cross-script variants with the Myanmar script and no in-script variants. For details, see Section 6, "Variants" in [Proposal-Oriya].

Digit Variants: The Oriya reference LGR does not include native digits, so there are no semantic variants defined. However, one Oriya digit is a near homoglyph of a European digit of a different value. U+0B68 (୨) ORIYA DIGIT TWO is a near homoglyph of U+0039 (9) DIGIT NINE. Should an extension be contemplated that adds native digits, adding such a homoglyph variant would require transitive variant relations between the two digits NINE, at which time this conflict would have to be resolved.

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 would be delegated, while any other equivalent label should be blocked. There is no preference among these variants.

This LGR does not define allocatable variants.

The specification of variants in this reference LGR follows the guidelines in [RFC 8228].

Character Classes

The basic characters in Oriya are classified into eight main categories. They are Consonants, Vowels, Matra, Halant, Nukta, Visarga, Candrabindu and Anusvara.

Consonants: The Oriya script is a syllabic alphabet in which all consonants have an inherent vowel. Diacritics, which can appear above, below, before, or after the consonant they belong to, are used to change the inherent vowel. More details in Section 3.5, "Structured consonants" and Section 3.6, "Unstructured consonants" in [Proposal-Oriya].

Vowels and Matras: A dependent vowel sign or "matra" is used to represent a vowel sound that is not inherent to the consonant. It is always depicted in combination with a single consonant, or with a consonant cluster. When vowels occur independently the are written with standalone vowel letters. More details in Section 3.12, "Matra sign (Dependent Vowel)" in [Proposal-Oriya].

Halant: A Halant, also known as Virama, is used after a consonant to "strip" it of its inherent vowel. The Halant form of a consonant is the form produced by adding the Halant, encoded as U+0B4D ( ୍ ) ORIYA SIGN VIRAMA to the nominal shape. A Halant follows all but the last consonant in every Oriya syllable. More details in Section 3.7, "The Implicit Vowel Killer Halant" in [Proposal-Oriya].

Nukta: The nukta sign ( ଼ ) is used in the Oriya language just like in many other scripts used in South Asia. It can be commonly used with U+0B21 ( ଡ ), U+0B22 ( ଢ ). More details in Section 3.8, "Nukta" in [Proposal-Oriya].

Visarga: U+0B03 (ଃ) ORIYA SIGN VISARGA is frequently used in Sanskrit and represents a sound very close to /h/. More details in Section 3.9, "Visarga & Avagraha" in [Proposal-Oriya].

Nasalization:

Candrabindu: The Candrabindu denotes nasalization of the preceding vowel and consonants as in ଅଁଳା /ãala/name of seasonal fruit (U+0B05 U+0B01 U+0B33 U+0B3E). Oriya users commonly use it for writing the words and sounds of Sanskrit. More details in Section 3.10, "Nasalization: Candrabindu" in [Proposal-Oriya].

Anusvara: Anusvara replaces a conjunct group of a Nasal Consonant+Halant+Consonant belonging to a particular varga (plosive). The Anusvara represents a homorganic nasal. Before a non-varga consonant (non-plosive) the Anusvara represents a nasal sound. More details in Section 3.11, "Anusvara" in [Proposal-Oriya].

Whole Label Evaluation (WLE) and Context Rules

Common Rules

• Hyphen Restrictions — restrictions on the allowable placement of hyphens (no leading/ending hyphen and no hyphen in positions 3 and 4). These restrictions are described in section 4.2.3.1 of RFC 5891 [150]. They are implemented here as context rule on U+002D (-) HYPHEN-MINUS.
• Leading Combining Marks — restrictions on the allowable placement of combining marks (no leading combining mark). This rule is described in section 4.2.3.2 of RFC 5891 [150].

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].

Oriya-specific Rules

These rules have been formulated so that they can be adopted for LGR specification.

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

The rules are:

• 1. N: must be preceded by C1
• 1. B: must be preceded by V, C, N or M
• 3. X: must be preceded by V, C, N or M
• 4. D: must be preceded by V, C, N or M
• 5. H: must be preceded by C or N
• 6. M: must be preceded by C or N

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

Methodology and Contributors

This reference LGR for Oriya for the 2nd Level has been developed by Michel Suignard and Asmus Freytag, based on the Root Zone LGR for Oriya and information contained or referenced therein, see [RZ-LGR-4-Orya]. Suitable extensions for the second level have been applied according to the [Guidelines]. The original proposal for a Root Zone LGR for the Oriya 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-Oriya], 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
(Accessed on 13 Nov. 2017)

[Proposal-Oriya]

Neo-Brahmi Generation Panel, "Proposal for an Oriya Script Root Zone Label Generation Rule-set ", 6 March 2019,
https://www.icann.org/en/system/files/files/proposal-oriya-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

[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-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-Orya]

ICANN, Root Zone Label Generation Rules for the Oriya Script (und-Orya) , 5 November 2020 (XML)
https://www.icann.org/sites/default/files/lgr/lgr-4-oriya-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 Oriya script for the second level please see details in the Table of References below. References [0] and [6] 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-Oriya] 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.

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	35	{0B15-0B28 0B2A-0B30 0B32-0B33 0B36-0B39 0B5F 0B71}		Any Oriya consonant
M	Tag=Matra	11	{0B3E-0B43 0B47-0B48 0B4B-0B4C 0B56}		Any Oriya vowel sign
V	Tag=Vowel	11	{0B05-0B0B 0B0F-0B10 0B13-0B14}		Any Oriya vowel letter
N	Tag=Nukta	1	{0B3C}		The Oriya Nukta
C1	Tag=C1	2	{0B21-0B22}		Specific consonants preceding Oriya Nukta
hyphen	Tag=Hyphen	1	{002D}		The Hyphen-minus character ⍟
implicit	Tag=Anusvara	1	{0B02}		The character tagged as Anusvara
implicit	Tag=Candrabindu	1	{0B01}		The character tagged as Candrabindu
implicit	Tag=Common-digit	10	{0030-0039}		Any character tagged as Common-digit
implicit	Tag=Halant	1	{0B4D}		The character tagged as Halant
implicit	Tag=Visarga	1	{0B03}		The character tagged as Visarga
implicit	Tag=sc:Mlym	1	{0D20}		Any character tagged as Malayalam
implicit	Tag=sc:Mymr	2	{101D 1031}		Any character tagged as Myanmar
implicit	Tag=sc:Orya	62	{0B01-0B03 0B05-0B0B 0B0F-0B10 0B13-0B28 0B2A-0B30 0B32-0B33 0B36-0B39 0B3C 0B3E-0B43 0B47-0B48 0B4B-0B4D 0B56 0B5F 0B71}		Any character tagged as Oriya
implicit	Tag=sc:Zyyy	11	{002D 0030-0039}		Any character tagged as Common

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-C1	([:C1:])← ⚓		✔	C		Section 7, WLE 1: N must be preceded by C1
follows-V-C-N-or-M	([:V:]|[:C:]|[:N:]|[:M:])← ⚓		✔	C		Section 7, WLE 2: B must be preceded by V, C, N or M; WLE 3: X must be preceded by V, C, N or M; WLE 4: D must be preceded by V, C, N or M
follows-C-or-N	([:C:]|[:N:])← ⚓		✔	C		Section 7, WLE 5: H must be preceded by C or N; WLE 6: M must be preceded by C or N

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 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) ⍟