ANSI Common Lisp   2 Syntax   2.4 Standard Macro Characters   2.4.8 Sharpsign

2.4.8.5 Sharpsign Colon

Syntax: #:<<symbol-name>>

#: introduces an uninterned symbol whose name is symbol-name. Every time this syntax is encountered, a distinct uninterned symbol is created. The symbol-name must have the syntax of a symbol with no package prefix.

For information on how the Lisp reader prints uninterned symbols, see Section 22.1.3.3 Printing Symbols.