CMU Common Lisp implements characters according to Common Lisp: the
Language II. The main difference from the first version is that
character bits and font have been eliminated, and the names of the
types have been changed. base-character is the new
equivalent of the old string-char. In this implementation,
all characters are base characters (there are no extended characters.)
Character codes range between 0 and 255, using the ASCII
encoding.
Table 2.1 tbl:chars shows characters
recognized by CMU Common Lisp.