Characters that are classified as graphic , or displayable, are each associated with a glyph, a visual representation of the character.
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 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.