A character is an object that represents a unitary token (e.g., a letter, a special symbol, or a "control character") in an aggregate quantity of text (e.g., a string or a text stream).
Common Lisp allows an implementation to provide support for international language characters as well as characters used in specialized arenas (e.g., mathematics).
The following figures contain lists of defined names applicable to characters.
Figure 13–1 lists some defined names relating to character attributes and character predicates.
| alpha-char-p | char-not-equal | char> |
| alphanumericp | char-not-greaterp | char>= |
| both-case-p | char-not-lessp | digit-char-p |
| char-code-limit | char/= | graphic-char-p |
| char-equal | char< | lower-case-p |
| char-greaterp | char<= | standard-char-p |
| char-lessp | char= | upper-case-p |
Figure 13–2 lists some character construction and conversion defined names.
| char-code | char-name | code-char |
| char-downcase | char-upcase | digit-char |
| char-int | character | name-char |