Graphic character
Encyclopedia
In ISO/IEC 646
ISO/IEC 646
ISO/IEC 646:1991, Information technology — ISO 7-bit coded character set for information interchange, is an ISO standard that since its first edition in 1972 has specified a 7-bit character code from which several national standards are derived...

 (commonly known as ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...

) and related standards including ISO 8859 and Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

, a graphic character is any character intended to be written, printed, or otherwise displayed in a form that can be read by humans. In other words, it is any encoded character
Character encoding
A character encoding system consists of a code that pairs each character from a given repertoire with something else, such as a sequence of natural numbers, octets or electrical pulses, in order to facilitate the transmission of data through telecommunication networks or storage of text in...

 that is associated with one or more glyph
Glyph
A glyph is an element of writing: an individual mark on a written medium that contributes to the meaning of what is written. A glyph is made up of one or more graphemes....

s.

ISO/IEC 646

In ISO 646, graphic characters are contained in rows 2 through 7 of the code
Code
A code is a rule for converting a piece of information into another form or representation , not necessarily of the same type....

 table. However, two of the characters in these rows, namely the space character SP at row 2 column 0 and the delete character DEL (also called the rubout character) at row 7 column 15, require special mention.

The space is considered to be both a graphic character and a control character
Control character
In computing and telecommunication, a control character or non-printing character is a code point in a character set, that does not in itself represent a written symbol.It is in-band signaling in the context of character encoding....

 in ISO 646; this is probably due to it having a visible form on computer terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

s but a control function (of moving the print head) on teletypes.

The delete character is strictly a control character, not a graphic character. This is true not only in ISO 646, but also in all related standards including Unicode. However, many modern character sets deviate from ISO 646, and as a result a graphic character might occupy the position originally reserved for the delete character.

Unicode

In Unicode, Graphic characters are those with General Category Letter, Mark, Number, Punctuation, Symbol or Zs=space. Other code points (General categories Control, Zl=line separator, Zp=paragraph separator) are Format, Control, Private Use, Surrogate, Noncharacter or Reserved (unassigned).
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