ANSI Common Lisp 15 Arrays 15.1 Array Concepts
15.1.2 Specialized Arrays
An array can be a general array,
meaning each element may be any object,
or it may be a specialized array,
meaning that each element must be of a restricted type.
The phrasing "an array specialized to type <<type>>"
is sometimes used to emphasize the element type of an array.
This phrasing is tolerated even when the <<type>> is t,
even though an array specialized to type t
is a general array, not a specialized array.
The next figure lists some defined names that are applicable to array
creation, access, and information operations.
General Purpose Array-Related Defined Names
188.8.131.52 Array Upgrading
184.108.40.206 Required Kinds of Specialized Arrays