11.1.2.6 The KEYWORD Package

The KEYWORD package contains symbols, called keywords_1, that are typically used as special markers in programs and their associated data expressions_1.

Symbol tokens that start with a package marker are parsed by the Lisp reader as symbols in the KEYWORD package; see Symbols as Tokens. This makes it notationally convenient to use keywords when communicating between programs in different packages. For example, the mechanism for passing keyword parameters in a call uses keywords_1 to name the corresponding arguments; see Ordinary Lambda Lists.

Symbols in the KEYWORD package are, by definition, of type keyword.