PREG_CLASS_CJK
constant PREG_CLASS_CJK
Matches CJK (Chinese, Japanese, Korean) letter-like characters.
This list is derived from the "East Asian Scripts" section of http://www.unicode.org/charts/index.html, as well as a comment on http://unicode.org/reports/tr11/tr11-11.html listing some character ranges that are reserved for additional CJK ideographs.
The character ranges do not include numbers, punctuation, or symbols, since these are handled separately in search. Note that radicals and strokes are considered symbols. (See http://www.unicode.org/Public/UNIDATA/extracted/DerivedGeneralCategory.txt)