Caret

Caret is the name used familiarly for the character , (the circumflex and a circumflex accent) provided on most QWERTY keyboards by typing . 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 formal ASCII standard (X3.64.1977) calls it a "circumflex". 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 or ). 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 x5E for an up-arrow . However, the 1965 ISO/IEC 646 standard defined code point x5E 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. In 1967, the second revision of ASCII followed suit. Overprinting to add an accent mark was not always supported well by printers, and was almost never possible on video terminals. Instead, precomposed characters were eventually created to show the accented letters. The freestanding circumflex (which had come to be called a caret) quickly became reused for many other purposes, such as in computer languages and mathematical notation.