L2/25-031

This file excerpts the Han Character Repertoire from the Root Zone Label Generation Rules (RZ-LGR-5)[RZ-LGR-5], reduced by two characters, U+3005 々 and U+3006 〆, which form part of the Han script but are not CJK Unified ideographs.

The set retained here represents a combination of common registry practice for East Asian ccTLD registries and has been proposed as the subset of Han characters that should be considered in common use for default identifiers. It is proposed that all present and future CJK Unified Ideographs outside this set should be given Identifier_Type=Uncommon_Use.

The immediate source for this document, the Root Zone LGR [RZ-LGR-5] specifies an integrated collection of Label Generation Rules for the Root Zone. For more details on the Root Zone LGRs and their development, see “Root Zone Label Generation Rules (RZ LGR-5): Overview and Summary” [RZ-LGR-5-Overview].

Label Generation Rules are expressed using a standard format defined in “Representing Label Generation Rulesets in XML” [RFC 7940]. For readability, a non-normative HTML presentation is available for each of the XML files. That presentation not only provides a formatted view but is augmented with annotations derived from the Unicode Character Database, as well as with summary data and common explanatory text. For purposes of this document, the original source file has been excerpted and a corresponding HTML presentation prepared from it.

Element LGRs

The Root Zone Label Generation Rules (RZ LGR-5) include the following set of script-specific element LGRs containing CJK unified ideographs:

• Root Zone Label Generation Rules for the Chinese Script (und-Hani) [104]
• Root Zone Label Generation Rules for the Japanese Script (und-Jpan) [113]
• Root Zone Label Generation Rules for the Korean Script (und-Kore) [116]

Repertoire

This document is an extract of all CJK Unified ideographs from [RZ-LGR-5], which in turn is the cumulative repertoire of all the element LGRs that have been integrated into the corresponding version. Those repertoires in turn were developed based on [MSR-5], which is a subset of [Unicode 11.0]. No unified ideographs encoded after that cutoff are proposed here as common use.

This repertoire is slightly smaller than the set of unified ideographs that were included in [MSR-5]. First, 11 characters originally from IICORE were found to exceed what is needed for identifiers. Second, two characters that are part of the Han script but not CJK Unified Ideographs (U+3005 々 and U+3006 〆) have been removed.

For further details, see Section 3.2.1, “Repertoire” in [RZ-LGR-5-Overview] as well as [MSR-5] and script-specific documents linked here.

No restrictions were applied to this set that are specific to the DNS Root Zone. Indeed, the same set of common-use CJK unified ideographs is used in the Second-level Reference Label Generation Rules [RefLGR].

Repertoire Listing: Each code point or range is tagged with the script or scripts with which these repertoire elements are used. Each cites the version of the Unicode Standard in which the code points were first encoded. All repertoire elements cite each Element LGR containing that repertoire element as well as the language-specific source collections used in constructing the subset; see “References” below.

All code points are tagged with the current Identifier_Type as of Unicode 11.0.0.

Contributors

This excerpt was prepared by Asmus Freytag, based on published data found in [RZ-LGR-5] and reference information from [MSR-5]. For details on and contributors to those projects, see [RZ-LGR-5-Overview], in particular Section 2, “Process of Integration” and Section 8, “Contributors”. Ken Lunde and Markus Scherer contributed feedback to this document or the set of characters listed.

References

In the listing of the repertoire, references starting at [0] refer to Unicode Standard versions in which the corresponding code points were initially encoded. References [200] and [300] correspond to sources given in [Proposal-Chinese] for justifying the inclusion of for the corresponding code points. References [104], [113] and [116] correspond to the RZ-LGR tables for Chinese, Japanese and Korean, respectively. References using alphabetic keys indicate CJK source collections used to create [MSR-5], including [IIC] for the IICore set. Code points in the repertoire are listed with all the references that apply.

In addition, the following references are cited or mentioned in this document:

[MSR-5]

Integration Panel, “Maximal Starting Repertoire - MSR-5: Overview and Rationale”, 24 June 2021,
https://www.icann.org/en/system/files/files/msr-5-overview-24jun21-en.pdf

[Procedure]

[Proposal-Chinese]

Chinese Generation Panel, “Proposal for the Chinese Script Root Zone LGR”, 26 May 2020 (PDF),
https://www.icann.org/en/system/files/files/proposal-chinese-lgr-26may20-en.pdf

[Proposal-Chinese-Appendices]

Appendices to “Proposal for a Chinese Script Root Zone LGR”, 26 May 2020 (ZIP),
https://www.icann.org/en/system/files/files/proposal-chinese-lgr-appdendices-26may20-en.zip

[Proposal-Japanese]

Japanese Generation Panel, “Proposal for the Japanese Script Root Zone LGR”, 20 December 2021 (PDF),
https://www.icann.org/en/system/files/files/proposal-japanese-lgr-20dec21-en.pdf

[Proposal-Korean]

Korean Generation Panel, “Proposal for the Korean Script Root Zone LGR”, 1 May 2021 (PDF),
https://www.icann.org/en/system/files/files/proposal-korean-lgr-01may21-en.pdf

[RefLGR]

ICANN, “Second-Level Reference Label Generation Rules”,
https://www.icann.org/resources/pages/second-level-lgr-2015-06-21-en

[RFC 7940]

Davies, K. and A. Freytag, “Representing Label Generation Rulesets Using XML”, RFC 7940, August 2016,
https://www.rfc-editor.org/info/rfc7940

[RZ-LGR-5-Overview]

Integration Panel, “Root Zone Label Generation Rules (RZ LGR-5): Overview and Summary”, 26 May 2022 (PDF),
https://www.icann.org/sites/default/files/lgr/rz-lgr-5-overview-26may22-en.pdf

[RZ-LGR-5]

Integration Panel, “Root Zone Label Generation Rules (RZ-LGR-5)”, 26 May 2022 (XML),
https://www.icann.org/sites/default/files/lgr/rz-lgr-5-common-26may22-en.xml
non-normative HTML presentation:
https://www.icann.org/sites/default/files/lgr/rz-lgr-5-common-26may22-en.html

[Unicode 11.0]

The Unicode Consortium. The Unicode Standard, Version 11.0.0, (Mountain View, CA: The Unicode Consortium, 2018. ISBN 978-1-936213-19-1)
https://www.unicode.org/versions/Unicode11.0.0/

For details on references [0] and up and [104] and up, as well as the CJK source collections, please refer to the Table of References below, as well as to [RZ-LGR-5-Overview].