Cancel character explained

In telecommunication and character encoding, the term cancel character refers to a control character which may be either of:

1. "CAN", "Cancel", U+0018, or ^X 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.^[1]
   • In some Videotex formats, it stops any running macros.^{[2] [3]} In others, it clears the current line after the cursor position (compare).^[4]
2. "CCH", "Cancel Character", U+0094, or ESC T used to erase the previous character. This character was created as an unambiguous alternative to the much more common backspace character ("BS", U+0008), which has a now mostly obsolete alternative function of causing the following character to be superimposed on the preceding one.

Notes and References

1. 26 . Control set for newspaper text transmission . International Press Telecommunications Council . International Press Telecommunications Council . 1976-03-25.
2. 132 . 1987-07-31 . Primary Control Set of Data Syntax I of CCITT Rec. T.101 . CCITT . ITU-T.
3. 135 . 1987-07-31 . Primary Control Set of Data Syntax III of CCITT Rec. T.101 . CCITT . ITU-T.
4. 134 . 1987-07-31 . Primary Control Set of Data Syntax II of CCITT Rec. T.101 . CCITT . ITU-T.