Z-variant
In
Differences on the Z-axis
The Unicode philosophy of code point allocation for CJK languages is organized along three "axes." The X-axis represents differences in semantics; for example, the Latin capital A (U+0041 A) and the Greek capital alpha (U+0391 Α) are represented by two distinct code points in Unicode, and might be termed "X-variants" (though this term is not common). The Y-axis represents significant differences in appearance though not in semantics; for example, the traditional Chinese character māo "cat" (U+8C93 貓) and the simplified Chinese character (U+732B 猫) are Y-variants.[1]
The Z-axis represents minor typographical differences. For example, the Chinese characters (U+838A 莊) and (U+8358 荘) are Z-variants, as are (U+8AAA 說) and (U+8AAC 説). The glossary at Unicode.org defines "Z-variant" as "Two CJK unified ideographs with identical semantics and unifiable shapes,"[1] where "unifiable" is taken in the sense of Han unification.
Thus, were Han unification perfectly successful, Z-variants would not exist. They exist in Unicode because it was deemed useful to be able to "round-trip" documents between Unicode and other CJK encodings such as
Confusion
There is some confusion over the exact definition of "Z-variant." For example, in an
] treats both pairs as Z-variants.See also
References
- ^ a b "Glossary". www.unicode.org.
- ^ Huang, K.; Ko, Y.; Konishi, K.; Qian, H. (April 2004). "Joint Engineering Team (JET) Guidelines for Internationalized Domain Names (IDN) Registration and Administration for Chinese, Japanese, and Korean". tools.ietf.org.
- ^ "Unihan Database Lookup". www.unicode.org.
