This document specifies a set of Label Generation Rules (LGR) for the Greek script for the second level domain or domains identified above. The starting point for the development of this LGR can be found in the related Root Zone LGR [RZ-LGR-Grek]. The format of this file follows [RFC 7940]. This LGR is adapted from the “Reference LGR for the Second Level for the Greek Script” [Ref-LGR-und-Grek], for details, see Change History below.
For details and additional background on the Greek script, see “Proposal for a Greek Script Root Zone LGR” [Proposal-Greek].
The repertoire contains the 36 code points used in writing the Greek language, according to [Proposal-Greek]. The repertoire is a subset of [Unicode 11.0.0]. For details, see Section 5, “Repertoire” in [Proposal-Greek]. (The proposal cited has been adopted for the Greek script portion of the Root Zone LGR.)
No Greek code points from [MSR-5] have been excluded.
The repertoire includes code points used by the modern-day Greek language, which is the official language of Greece and Cyprus. The repertoire also covers the Pomak language, which is the only “non-Greek” language that uses Greek characters nowadays. For more details, see Section 5 “Repertoire” in [Proposal-Greek]).For the second level, the repertoire has been augmented with the ASCII digits, U+0030 to U+0039, plus U+002D HYPHEN-MINUS, for a total of 47 repertoire elements.
Any code points outside the Greek Script repertoire that are targets for out-of-repertoire variants would be included here only if the variant is listed in this file. In this case they are identified as a reflexive (identity) variant of type “out-of-repertoire-var”. Whether or not they are listed, they do not form part of the repertoire.
Repertoire Listing: Each code point or range is tagged with the script or scripts with which the code point is used and one or more other character categories. For each repertoire element, one or more references document sufficient justification for inclusion in the repertoire; see the “References” below.
The variants defined in this LGR are limited to those required for use in zones not shared with any other script. As such, this LGR does not define cross-script variants. However, using this LGR concurrently with any LGR for Armenian, Cyrillic, and Latin in the same zone will create potential cross-script issues. For details, see Section 6, “Variants” in [Proposal-Greek]. Mitigation of these cross-script variants can be addressed by using the Common LGR. For details, see Section 3, “Use of Multiple Reference LGRs in the Same Zone” in [Level-2-Overview]. In addition to variants defined by this LGR, the full variant information related to this script and required for concurrent use with the Armenian, Cyrillic, and Latin LGR(s) can be found in the following LGR: [Ref-LGR-Latin-Full-Variant-Script]
In-script variants defined in this LGR largely follow the methodology defined in Section 6, “Variants”, in [Proposal-Greek].
The LGR defines certain allocatable fallback variants as described in Section 4.5.5 “Allocatable Fallback Variants” in [Level-2-Overview]. A fallback variant is a variant label that uses substitute code points for code points or sequences not available (or not allowed) in some contexts, that would otherwise be required for a linguistically accurate rendering of some label.
When “fallback” variants are defined, two labels may be allocated: a single label with the spelling preferred by the applicant, plus a single fallback variant for that label. The fallback exclusively uses the fallback characters for any characters for which fallbacks are defined, while the “preferred” label may use any otherwise valid mix of code points. If the fallback variant is the one applied for, no other variant label is allocatable.
Allocatable fallback variants exists for the following cases:
In each of the fallback variant pairs defined above, the mapping type from the first element to the second is of type “fallback”, while the variant type for the other direction is “blocked”. In addition, the first element of each pair uses the reflexive mapping “r-original”. (By convention, the prefix “r-” marks a type used in a reflexive variant mapping, that is, it represents an instance of the original code point at that location in a variant label, see Section 5.3.4 in [RFC 7940].)
Variant Disposition: Except for limited exceptions for the fallback variants defined above, variants defined here result in a variant label disposition of “blocked”.
The specification of variants in this LGR follows the guidelines in [RFC 8228].
This LGR does not define named character classes.
By default, the LGR includes the rules and actions to implement the following restrictions mandated by the IDNA protocol. They are marked with ⍟.
This LGR does not define rules specific to the Greek script.
This LGR includes the default actions for LGRs as well as the action needed to invalidate labels with misplaced combining marks. They are marked with ⍟. For a description see [RFC 7940].
Because this LGR defines allocatable fallback variants the following default actions are applicable.
These actions resolve as “allocatable” any label where all variants are of type “fallback”, and as “valid” any label where all variants are of type “r-original”. Labels with a mix of variant types are resolved as “blocked”.
To account for original code points in a permuted variant, reflexive variant mappings with an “r-” prefix are used. (See [RFC 7940]). In particular, the mapping type “r-original” is given to any code point that has a fallback mapping, but that appears in its non-fallback form in the original label, and thus “maps to itself”.
Default actions that are triggered by the LGR-specific variant types described above limit the “allocatable” variant labels to those containing only unaccented vowel or nonfinal sigma variants or both, while disallowing mixed use of accented and unaccented vowels or final and nominal forms of sigma, except as in the original applied-for label.
Note that the mapping types for variants are not symmetric: they depend on which code point is considered the source or the target in a given mapping. As specified in [RFC 7940], when mapping types are evaluated code points in a label that are unchanged use the type of their “reflexive” mapping. Per [RFC 7940] the actions are always applied one after the other, and the evaluation stops at the first action that assigns a disposition to a given label.
The LGR in this document has been adapted from the corresponding Reference LGR for the Second Level. The Second Level Reference LGR for the Greek Script was developed by Michel Suignard and Asmus Freytag, based on the Root Zone LGR for the Greek script and information contained or referenced therein; see [RZ-LGR-Grek]. Suitable extensions for the second level have been applied according to the [Guidelines] and with community input. The original proposal for a Root Zone LGR for the Greek script, that this LGR is based on, was developed by the Greek Generation Panel. For more information on methodology and contributors to the underlying Root Zone LGR, see Sections 4 and 8 in [Proposal-Greek], as well as [RZ-LGR-Overview].
This version modifies the Second Level Reference LGR for the Greek Script [Ref-LGR-und-Grek] by injecting the complete (maximal) set of cross-repertoire variants, including any imposed by transitivity. Injected variants are marked by special comments. Any character classes, context and WLE rules required for testing are also imported. In all other respects, description or annotations have not been updated to reflect the injected variants. Any LGR elements that might pose a possible conflict when the LGR is used with the Common LGR for cross-repertoire variant resolution are clearly marked. All modifications are carried out mechanically; there may be an occasional context rule or similar that is injected because its definition relates to some repertoire element even though it can never be triggered by any label valid under the modified LGR.
The following general references are cited in this document:
For references consulted particularly in designing the repertoire for the Greek Script for the second level please see details in the Table of References below.
Reference [0] refers to the Unicode Standard version in which corresponding code points were initially encoded. Reference [101] corresponds to the source given in [Proposal-Greek] for justifying the inclusion of the corresponding code points. Entries in the table may have multiple source reference values. In the listing of whole label evaluation and context rules, reference [150] indicates the source for common rules.
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