simple-string, string, vector, simple-array, array, sequence, t

A simple string is a specialized one-dimensional simple array whose elements are of type character or a subtype of type character. When used as a type specifier for object creation, simple-string means (simple-array character (size)).

Abbreviating.

size — a non-negative fixnum, or the symbol *.

This denotes the union of all types (simple-array c (size)) for all subtypes c of character; that is, the set of simple strings of size size.