ANSI Common Lisp 2 Syntax 2.1 Character Syntax 2.1.4 Character Syntax Types
220.127.116.11 Constituent Characters
Constituent characters are used in tokens.
A token is a representation of a number or a symbol.
Examples of constituent characters are letters and digits.
Letters in symbol names are sometimes converted to
letters in the opposite case when the name is read;
see Section 23.1.2 Effect of Readtable Case on the Lisp Reader.
Case conversion can be suppressed by the use
of single escape or multiple escape characters.