# Regex Model Unicode Character Matching

The regex model supports matching Unicode characters, with the caveat that it operates in units of Unicode code points – each feature is assumed to correspond to a Unicode code point.

Note that in Unicode, there are so-called "combining characters", which means that a character can consist of several code points. This is a common way to express unusual combinations of diacritics.

Unicode provides so-called precomposed characters – characters (even with diacritics) which only consist of a single code point. To ensure that these are used, the user should use the Unicode normalization form NFC. (Notable exceptions are half-width Japanese kana with dakuten or handakuten diacritics – these have no precomposed form in Unicode.)