Cancel character: Difference between revisions

Revision as of 18:06, 10 March 2022

Revision as of 09:35, 8 December 2023

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{{short description|Either of two control codes used to delete or rescind preceding data or characters}}

In [[telecommunication]] and [[character encoding]], the term '''cancel character''' hasrefers theto a [[control character]] which may be followingeither meaningsof:

#A [[control character]] ("CAN", "Cancel", [[Basic Latin (Unicode block)|U+0018]], or [[caret notation|<code>^X</code>]]) used to indicate that the [[data]] with which it is associated are in [[error]] or are to be disregarded. Exact meaning can depend on protocol. For example:

#* In some journalistic text transmission formats, it signifies that the preceding word should be deleted; it is sometimes called "Kill Word" ("KW") in this context.<ref>{{cite iso-ir |number=26 |title=Control set for newspaper text transmission |sponsor=International Press Telecommunications Council |sponsor-link=International Press Telecommunications Council |date=1976-03-25}}</ref>

#* In some [[Videotex]] formats, it stops any running macros.<ref name="ir132">{{cite iso-ir |number=132 |date=1987-07-31 |title=Primary Control Set of Data Syntax I of CCITT Rec. T.101 |sponsor=CCITT |sponsor-link=ITU-T}}</ref><ref name="ir135">{{cite iso-ir |number=135 |date=1987-07-31 |title=Primary Control Set of Data Syntax III of CCITT Rec. T.101 |sponsor=CCITT |sponsor-link=ITU-T}}</ref> In others, it clears the current line after the cursor position (compare {{control code link|EL}}).<ref name="ir134">{{cite iso-ir |number=134 |date=1987-07-31 |title=Primary Control Set of Data Syntax II of CCITT Rec. T.101 |sponsor=CCITT |sponsor-link=ITU-T}}</ref>

#A [[control character]] ("CCH", "Cancel Character", [[UnicodeLatin-1 Supplement|U+0094]], or <code>ESC T</code>) used to erase the previous character. This character was created as an unambiguous alternative to the much more common backspace character ("BS", [[Basic Latin (Unicode block)|U+0008]]), which has a now mostly obsolete alternative function of causing the following character to be superimposed on the preceding one.

==References==