* Non-Unicode or missing PCRE unicode support: "/[^\S\xa0]/" * Unicode and PCRE unicode support: "/(?!\xa0)[\s\p{Z}]/u" * Unicode and PCRE unicode support in Chinese mode: "/(?!\xa0)[\s\p{Z}\p{Lo}]/u" * if PCRE unicode support is turned ON ("\P" is the negate class of "\p"): * \s : any whitespace character * \p{Z} : any separator * \p{Lo} : Unicode letter or ideograph that does not have lowercase and uppercase variants. Is used to chunk chinese words. * \xa0 : Unicode Character 'NO-BREAK SPACE' (U+00A0) *