ANSI Common Lisp   13 Characters   13.1 Character Concepts   13.1.4 Character Categories

13.1.4.1 Graphic Characters

A graphic character is one that has a standard textual representation as a single glyph, such as A or * or =. Space, which effectively has a blank glyph, is defined to be a graphic.

Of the standard characters, newline is non-graphic and all others are graphic; see Section 2.1.3 Standard Characters.

Characters that are not graphic are called non-graphic. Non-graphic characters are sometimes informally called "formatting characters" or "control characters."

#\Backspace, #\Tab, #\Rubout, #\Linefeed, #\Return, and #\Page, if they are supported by the implementation, are non-graphic.