To continue from the December 26, 2012 article, I should first point out that there is a relationship between these 1,002 proposed standardized variants and IVSes (Ideographic Variation Sequences). Standardized variants are standardized, hence their name. IVSes, on the other hand, are registered via a process that is described in UTS #37 and administered by the IVD Registrar (which happens to me at the moment).
Up until these 1,002 standardized variants were proposed in WG2 N4246, the higher-frequency—in terms of real-world usage—CJK Compatibility Ideographs already had registered IVSes. In fact, for all but one case, all Japanese-specific CJK Compatibility Ideographs now have two registered IVSes. One is registered in the “Adobe-Japan1″ IVD Collection, and the other is registered in the “Hanyo-Denshi” IVD Collection. (For those that are curious, the “Hanyo-Denshi” IVD Collection is missing a registered IVS for U+FA15 [凞].)
IVD collections are based on glyph sets. In other words, a solution that involves IVSes would have necessarily crossed over into the territory of glyphs. Thus, the beauty of these standardized variants as a solution is three-fold:
- It does not cross over into the territory of glyphs.
- All 1,002 CJK Compatibility Ideographs can be handled at once. It takes time to register IVSes, and some CJK Compatibility Ideographs, such as those from North Korea (DPRK), have unclear sources.
- Neither IVD collection—”Adobe-Japan1″ nor “Hanyo-Denshi”—is preferred nor used.
To elaborate on the second point, the vast majority of remaining CJK Compatibility Ideographs map to CNS 11643. An IVS-based solution would require an IVD collection to register IVSes for them. This would apply to all CJK Compatibility Ideographs. It would likely take years to register IVSes to cover all 1,002 CJK Compatibility Ideographs.
Stay tuned for Part 3…