Caret

Caret (from Latin caret 'it lacks') is the name used familiarly for the character ^ provided on most QWERTY keyboards by typing ⇧ Shift+6. The symbol has a variety of uses in programming and mathematics. The name "caret" arose from its visual similarity to the original proofreader's caret, ‸, a mark used in proofreading to indicate where a punctuation mark, word, or phrase should be inserted into a document. The ASCII standard (X3.64.1977) calls it a "circumflex"; the Unicode standard calls it a "circumflex accent", although it is no longer practicable to use it for that purpose.

History

Typewriters

On typewriters designed for languages that routinely use diacritics (accent marks), there are two possible ways to type these: keys can be dedicated to precomposed characters (with the diacritic included); alternatively a dead key mechanism can be provided. With the latter, a mark is made when a dead key is typed but, unlike normal keys, the paper carriage does not move on and thus the next letter to be typed is printed under the accent. The ^ symbol was originally provided in typewriters and computer printers so that circumflex accents could be overprinted on letters (as in ô or ŵ).

Transposition into ISO/IEC 646 and ASCII

The incorporation of the circumflex symbol into ASCII is a consequence of this prior existence on typewriters: this symbol did not exist independently as a type or hot-lead printing character. The original 1963 version of the ASCII standard used the code point 0x5E for an up-arrow ↑. However, the 1965 ISO/IEC 646 standard defined code point 0x5E as one of five available for national variation, with the circumflex ^ diacritic as the default and the up-arrow as one of the alternative uses.