BacktickThe backtick is a typographical mark used mainly in computing. It is also known as backquote, grave, or grave accent. The character was designed for typewriters to add a grave accent to a (lower-case) base letter, by overtyping it atop that letter. On early computer systems, however, this physical dead key+overtype function was rarely supported, being functionally replaced by precomposed characters. Consequently, this ASCII symbol was rarely (if ever) used in computer systems for its original aim and became repurposed for many unrelated uses in computer programming.
CaretCaret 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".
At signThe at sign, , is an accounting and invoice abbreviation meaning "at a rate of" (e.g. 7 widgets @ £2 per widget = £14), now seen more widely in email addresses and social media platform handles. It is normally read aloud as "at" and is also commonly called the at symbol, commercial at, or address sign. The absence of a single English word for the symbol has prompted some writers to use the French arobase or Spanish and Portuguese arroba, or to coin new words such as ampersat and asperand, or the (visual) onomatopoeia strudel, but none of these have achieved wide use.
Shift keyThe Shift key is a modifier key on a keyboard, used to type capital letters and other alternate "upper" characters. There are typically two shift keys, on the left and right sides of the row below the home row. The Shift key's name originated from the typewriter, where one had to press and hold the button to shift up the case stamp to change to capital letters; the shift key was first used in the Remington No. 2 Type-Writer of 1878; the No. 1 model was capital-only.
Less-than signThe less-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the left, , has been found in documents dated as far back as the 1560s. In mathematical writing, the less-than sign is typically placed between two values being compared and signifies that the first number is less than the second number. Examples of typical usage include < 1 and −2 < 0.
Dollar signThe dollar sign, also known as peso sign, is a currency symbol consisting of a capital "S" crossed with one or two vertical strokes (ordependingontypeface),usedtoindicatetheunitofvariouscurrenciesaroundtheworld,includingmostcurrenciesdenominated"peso"and"dollar".Theexplicitlydouble−barredsigniscalledcifra~oinPortuguese.Thesignisalsousedinseveralcompoundcurrencysymbols,suchastheBrazilianreal(R) and the United States dollar (US$): in local use, the nationality prefix is usually omitted. Null characterThe null character (also null terminator) is a control character with the value zero. It is present in many character sets, including those defined by the Baudot and ITA2 codes, ISO/IEC 646 (or ASCII), the C0 control code, the Universal Coded Character Set (or Unicode), and EBCDIC. It is available in nearly all mainstream programming languages. It is often abbreviated as NUL (or NULL, though in some contexts that term is used for the null pointer). In 8-bit codes, it is known as a null byte.
Rich Text FormatThe Rich Text Format (often abbreviated RTF) is a proprietary with published specification developed by Microsoft Corporation from 1987 until 2008 for cross-platform document interchange with Microsoft products. Prior to 2008, Microsoft published updated specifications for RTF with major revisions of Microsoft Word and Office versions. Most word processors are able to read and write some versions of RTF. There are several different revisions of RTF specification; portability of files will depend on what version of RTF is being used.
Hyphen-minusThe hyphen-minus is the most commonly used type of hyphen, widely used in digital documents. In ASCII or on most keyboards it is the only character that resembles a minus sign or a dash so it is also used for these. The name "hyphen-minus" derives from the original ASCII standard, where it was called "hyphen (minus)". The character is referred to as a "hyphen", a "minus sign", or a "dash" according to the context where it is being used.
ANSI CANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Historically, the names referred specifically to the original and best-supported version of the standard (known as C89 or C90). Software developers writing in C are encouraged to conform to the standards, as doing so helps portability between compilers.
