ANSI Common Lisp  2 Syntax 2.1 Character Syntax 2.1.4 Character Syntax Types
2.1.4.5 Multiple Escape CharactersA pair of multiple escape characters is used to indicate that an enclosed sequence of characters, including possible macro characters and whitespace2 characters, are to be treated as alphabetic2 characters with case preserved. Any single escape and multiple escape characters that are to appear in the sequence must be preceded by a single escape character.Vertical-bar is a multiple escape character in standard syntax. |