Homoglyph
See: Maximal Starting Repertoire — MSR-2 Overview and Rationale. Section 5.7.
The Integration Panel, for the purpose of creating the MSR, generally did not consider confusability between code points that otherwise qualify for inclusion. The expectation is that each Generation Panel will apply particular scrutiny in such cases and will propose whether such cases should be handled by defining blocked variants, by not including code points in the LGR or by relying on standard processes outside the LGR to address the issue.
Homoglyphs are characters which are of essentially identical appearance by design, instead of merely similar appearance. In many cases, homoglyphs arise because Unicode assigned a duplicate code point to the “same” character, based on different use, or to avoid having to give a single character membership in multiple scripts. Often the reason that characters may be homoglyphs is because of historical derivation from the same source or because of having been adopted (borrowed) from another script. Where confusability is based on homoglyphs, the Integration Panel makes a distinction between homoglyphs of PVALID code points and homoglyphs of code points that are not PVALID in IDNA 2008.
The expectation of the Integration Panel is that homoglyphs of single PVALID code points will be addressed in each Generation Panel's LGR proposal, and further, that the LGR
will exclude homoglyphs from the repertoire or define them as blocked variants, unless the Generation Panel can provide an acceptable justification for a different treatment.
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See: Guidelines for Developing Script-Specific Label Generation Rules for Integration into the Root Zone LGR. Section B.11.2.
The Cyrillic, Greek and Latin scripts provide an example of related scripts where a large number of cross script homoglyphs exist. A consistent treatment of these across scripts might be achieved by coordination.
MSR
Maximal Starting Repertoire. Current version is 2. See Maximal Starting Repertoire — MSR-2 Overview and Rationale. Sections 1 and 2.
Procedure
See: Procedure to Develop and Maintain the Label Generation Rules for the Root Zone in Respect of IDNA Labels.
Separable
From Maximal Starting Repertoire — MSR-2 Overview and Rationale. Section 3.3:
Separable scripts are not mutually related. As a consequence, they can be considered independently, both for inclusion in the MSR, but also for purposes of integration. LGRs for separable scripts can be reviewed independently by the Integration Panel without the risk from possible interactions. The same is not true for related scripts.
