- char-alphabetic? Cprocedure
- char-numeric? Cprocedure
- char-lower-case? Cprocedure
- char-upper-case? Cprocedure
- char-whitespace? Cprocedure
- char-downcase Cprocedure
- char-upcase Cprocedure
- char-foldcase Cprocedure
- char-ci=? C1 C2procedure
- char-ci>? C1 C2procedure
- char-ci<? C1 C2procedure
- char-ci>=? C1 C2procedure
- char-ci<=? C1 C2procedure
- string=? S Sprocedure
- string>? S1 S2procedure
- string<? S1 S2procedure
- string>=? S1 S2procedure
- string<=? S1 S2procedure
- string-downcase S1procedure
- string-upcase S1procedure
- string-foldcase S1procedure
UNICODE-aware character and string operations (unless UNICODE support is disabled).