- - The wide-character string pointed to by <EM>wch</EM>. The
- string must be L'\0' terminated, contain at most one
- character with strictly positive width, which must be
- the first, and contain no characters of negative
- width.
+ <STRONG>o</STRONG> The wide-character string pointed to by <EM>wch</EM>. The
+ string must be L'\0' terminated, contain at most one
+ spacing character, which must be the first.
+
+ Up to <STRONG>CCHARW_MAX</STRONG>-1 nonspacing characters may follow.
+ Additional nonspacing characters are ignored.
+
+ The string may contain a single control character
+ instead. In that case, no nonspacing characters are
+ allowed.