The typographic character @, the at sign, denotes a pan-lingual abbreviation of the word 'at'. It evolved from the phrase "at the rate of" in accounting and commercial invoices, e.g. “7 widgets @ $2 ea. = $14”. Nowadays, this commercial character is ubiquitous because of its use in e-mail addresses. In English, it is informally pronounced as at, and can be referred to as the at sign or the at symbol. Its official, typographic character nomenclature is commercial at in the ANSI/CCITT/Unicode character encoding standards. Some historical names are mentioned in the "History" section below.
These are some theories about the origin of the commercial at character in modern usage:
- The symbol developed as a mercantile shorthand symbol of "each at" -- the symbol resembling a small "a" inside a small "e" -- to distinguish it from the different "at" (symbolized by the mere letter "a") or "per." For example, the cost of "12 apples @ $1" would be $12, whereas the cost of "12 apples a $1" would be $1 -- a crucial and necessary distinction.
- Medieval monks abbreviated the Latin word ad (at, toward, by, about) next to a numeral.
- It was a 15th-century Spanish unit of weight: arroba = jar.
- The abbreviated Greek preposition ανά, ana, meaning at the rate of, its commercial usage.
- An Italian academic claims to have traced the @ symbol to the Italian Renaissance, in a Venetian mercantile document signed by Francesco Lapi on May 4, 1537. The document is about commerce with Pizarro, in particular the price of an @ of wine in Peru; @ meant amphora (Italian anfora; Spanish and Portuguese arroba). Currently, the word arroba means the at-symbol and a unit of weight (cf. below). In this usage, the symbol represents one amphora, a unit of weight and volume based upon the capacity of the standard terracotta jar, and entered modern meaning and use as "at the rate of" in northern Europe.
- From Norman French "à" meaning "at" in the "each" sense, i.e. "2 widgets à £5.50 = £11.00" is the accountancy shorthand notation in English commercial vouchers and ledgers to the 1990s, when the e-mail usage superseded the accountancy usage. It also is so used in Modern French and Swedish; in this view, the at-symbol is a stylised form of à that avoids raising the writing hand from the page in drawing the symbol; this compromise between @ and à in French handwriting is in street market signs.
- In - especially English - science and technical literature used to describe the conditions under which data are valid or a measurement has been made. E.g. the density of saltwater may read d = 1.050 g/cm³ @ 15°C (read "at" for @), density of a gas d = 0,150 g/L @ 20°C, 1 bar, or noise of a car 81 dB @ 80 km/h (speed).
The @ was present in the 1902 model Lambert typewriter made by Lambert Typewriter Company of New York. Its inclusion in the original 1963 ASCII character set went unremarked as it was a standard commercial typewriter character, e.g. the 1961 IBM Selectric typewriter's keyboard included the @ (at-symbol).
In contemporary English usage, @ is a commercial symbol, meaning at and at the rate of. It has been used, rarely, in financial documents or grocers' price tags, and is not used in standard typography.
Its most familiar contemporary use is in e-mail addresses (transmitted by SMTP), as in email@example.com (the user jdoe working at the computer named example in the domain com). Ray Tomlinson is credited with introducing this usage in 1971. This idea of the symbol representing located at in the form "user@host" also is seen in other tools and protocols: the command
ssh firstname.lastname@example.org tries to establish a ssh connection to the computer with the hostname www.example.com using the username jdoe.
On the Indian Subcontinent the contemporary way of verbally expressing the @ is still by saying "at the rate of", even when referring to its use in an email address. With the growing use of Information Technology companies in India for support and call centres, hearing "at the rate of" in the context of an email address can potentially confuse North American and other native English-speaking technologists.
The @ is used in various programming languages though there is not a consistent theme to its usage. For example, in Perl, @ prefixes variables which contain arrays; in PHP, it is used just before a function to make the interpreter suppress errors that would be generated when using that function; in C#, @ is the verbatim literal string operator meaning that the string should be used "as is" and not be processed for escape sequences; in Python 2.4 and up, it is used to decorate a function (wrap the function in another one at creation time); in Java, it is used to denote annotations, a kind of metadata, since version 5.0; in Ruby, @ prefixes instance variables, and @@ prefixes class variables.
In modal logic, specifically when representing possible worlds, @ is sometimes used as a logical symbol to denote the actual world (the world we are 'at').
The @ is used as an alternative political spelling for typing in some Romance languages as a gender-neutral substitute for the masculine "o" in mixed sex groups and in cases where the sex is unknown. For example, the Portuguese/Spanish word "amigos" (friends), which can mean men and women friends or all men friends would be replaced with "amig@s", unless the writer is sure the group referred to is all-male (amigos) or all-female (amigas). The character is intended to resemble a digraph of both the masculine letter "o" and the feminine letter "a". The usefulness of this is debatable; in Portuguese/Spanish, the masculine grammatical gender may include both men and women, while the feminine gender is exclusively for and about women; there is no neuter gender for most nouns. Some advocates of gender-neutral language-modification feel that using the male grammatical gender as a generic gender designator indicates implicit linguistic disregard for women. Many Portuguese/Spanish speakers think that this usage of the @ (at-sign) degrades Portuguese/Spanish; some argue it is just more cultural imperialism; generally, this construction is used only in personal, informal writing, and has no established pronunciation. Alternative forms would be amigos/as and amigⒶs using the circle-A of anarchism as the bisexual digraph.
In chemical formulae, the @ is used to denote trapped atoms or molecules. For instance, La@C60 means lanthanum inside a fullerene cage.
In most roguelike games (e.g. Angband and NetHack), @ denotes the player character. Some roguelikes also use @ to denote any human being. This usage is because the @ resembles an overhead view of a person's head and shoulders.
The @ is also used sometimes (e.g. articles about missing persons, obituaries, brief reports) to denote an alias after a person's proper name, for instance: "John Smith @ Jean Smyth".
The @ may sometimes be used to represent a schwa, as the actual schwa character "ə" may be difficult to produce in many computers. It is used in this capacity in the ASCII IPA or Kirshenbaum IPA scheme.
On some online forums without proper Threaded discussions, @ is used to denote a reply, for instance: "@Jane" to respond to a comment Jane made earlier.
In online discourse, the @ is used by some anarchists as a substitute for the traditional circle-A .
It is frequently used in Leet as a substitute for the letter A.
In Malagasy, @ is an informal abbreviation for the prepositional form amin'ny.
In IRC, it is often shown before a user's nick to mark the operator of a channel.
In some cases, the "at sign" is used for "attention" in emails originally sent to someone else. For example if the email was sent from Catherine to Steve, but in the body of the email, Catherine wants to make Keirsten aware of something, Catherine will start the line "@Keirsten" to indicate to Keirsten that the following sentence concerns her. This also helps with mobile email users who can not see bold or color in email.
"Commercial at" in other languages
In most languages other than English, @ was less common before e-mail became widespread in the mid-1990s, although most typewriters included the symbol. Consequently, it is often perceived in those languages as denoting "The Internet", computerization, or modernization in general.
- In Armenian it is "shnik" which means puppy.
- In Azeri it is at (using the English pronunciation).
- In Basque it is called a bildua ("rounded a")
- In Belarusian it's called "сьлімак" ("helix", "snail")
- In Bulgarian it is called кльомба ("klyomba", means nothing else) or маймунско а (majmunsko a "monkey A").
- In Catalan it is called arrova.
- In Chinese
- In mainland China it is quan a (圈a), meaning "circled a" or hua a (花a, lacy a).
- In Taiwan it is xiao laoshu (小老鼠), meaning "little mouse", or laoshu hao (老鼠號, "mouse sign").
- In Hong Kong it is at (using the English pronunciation).
- In Croatian it is informally called manki, coming from the local pronunciation of the English word, monkey. The Croatian word for monkey, majmun, is not used to denote the at sign.
- In Czech and Slovak it is called zavináč (rollmops).
- In Danish it is snabel-a ("(elephant's) trunk-a").
- In Dutch it is called apenstaartje ("little monkey-tail").
- In Esperanto it is called ĉe-signo ("at" - for the e-mail use, with an address pronounced zamenhof ĉe esperanto punkto org), po-signo ("each" -- refers only to the mathematical use) or heliko ("snail").
- In Faroese it is kurla (sounds "curly"), hjá ("at"), tranta and snápila ("(elephant's) trunk-a").
- In Finnish it was originally called taksamerkki ("fee sign") or yksikköhinnan merkki ("unit price sign"), but these names are long obsolete and now rarely understood. Nowadays, it is officially ät-merkki, according to the national standardization institute SFS; frequently also spelled "at-merkki". Other names include kissanhäntä, ("cat's tail") and miukumauku ("the miaow sign").
- In French it is arobase or arrobe or a commercial (though this is most commonly used in French-speaking Canada, and should normally only be used when quoting prices; it should always be called arobase or, better yet, arobas when in an e-mail address), and sometimes a dans le rond (a in the circle). Same origin as Spanish which could be derived from Arabic, ar-roub. Southern French speakers refer to it as le petit escargot ("little snail") due to its appearance, or le a avec la queue du marsupilami, in reference to a comic.
- In German it sometimes used to be referred to as Klammeraffe (meaning "spider monkey"). Klammeraffe refers to the similarity of the @ to the tail of a monkey grabbing a branch. Lately, it is mostly called at just like in English
- In Greek, it is most often referred to as papaki (παπάκι), meaning "duckling," due to the similarity it bears with comic character designs for ducks.
- In Greenlandic Inuit language - it is called aajusaq meaning "a-like" or "something that looks like a"
- In Hebrew it is colloquially known as shtrudel (שטרודל). The normative term, invented by the Academy of the Hebrew Language, is krukhit (כרוכית), which is a Hebrew word for strudel.
- In Hindi it is "at" (using the English pronunciation).
- In Hungarian it is officially called kukac ("worm, mite, or maggot").
- In Icelandic it is referred to as "at merkið (the at-sign)" or "hjá" which is a direct translation of at.
- In Indonesian it is et,a bundar, meaning "circle A".
- In Italian it is chiocciola ("snail") or a commerciale, sometimes at (pronounced more often /ɛt/, and rarely /at/, instead of /æt/) or ad.
- In Japanese it is called attomāku (アットマーク, "at mark"). The word is a wasei-eigo, which are Japanese vocabulary forged from the English language or Gairaigo foreign loan words in general. It is sometimes called naruto, because of Naruto whirlpool or food (kamaboko).
- In Kazakh it is officially called айқұлақ ("moon's ear"), sometimes unofficial as ит басы ("dog's head").
- In Korean it is called golbaeng-i (골뱅이; bai top shells), a dialectal form of daseulgi (다슬기), a small freshwater snail with no tentacles.
- In Latvian it is pronounced same as in English, but, since in Latvian [æ] is written as "e" not "a" (as in English), it's sometimes written as et.
- In Lithuanian it is eta (equivalent to English at but with Lithuanian ending)
- In Luxembourgish it used to be called Afeschwanz (monkey-tail), but due to widespread use it is now pronounced 'at' like in English.
- In Macedonian it is called мајмунче (pronun. my-moon-cheh, little monkey)
- In Morse Code it is known as a "commat," consisting of the Morse code for the "A" and "C" run together as one character: (·--·-·). This occurred in 2004 .
- In Norwegian it is officially called krøllalfa ("curly alpha" or "alpha twirl"). (The alternate alfakrøll is also common. Sometimes Snabel a(trunk a, as in elephant's trunk) is used. )
- In Persian it is at (using the English pronunciation).
- In Portuguese, it is called 'arroba'. (Some say that in Portugal it is called 'caracol' (snail) although this is yet to be confirmed). The word arroba is also used for a weight measure in Portuguese. While there are regional variations, one arroba is typically considered as representing approximately 25 pounds, 11.5 kg, and both the weight and the symbol are called arroba. In Brazil, cattle are still priced by the arroba — now rounded to 15 kg. (This occurs because the same sign was usde to reprsent the same measure.)
- In Polish it is called, both officially and commonly małpa (monkey); sometimes also małpka (little monkey) or bałwanek (little snowman).
- In Romanian it is Coadă de maimuţă (monkey-tail) or "a-rond"
- In Russian it is most commonly sobaka (собака) (dog).
- In Serbian it is called лудо А (ludo A crazy A) or мајмун (majmun monkey)
- In Slovenian it is called afna (little monkey)
- In Spanish speaking countries it denotes a pre-metric unit of weight. While there are regional variations in Spain and Mexico it is typically considered to represent approximately 25 pounds (11.5 kg), and both the weight and the symbol are called arroba. It has also been used as a unit of volume for wine and oil.
- In Swedish it is called snabel-a ("(elephant's) trunk-a"), Kanelbulle (cinnamon bun) or simply "at" like in the English language.
- In Swiss German it is commonly called Affeschwanz ("monkey-tail").
- In Tagalog it is commonly called utong ("nipple").
- In Turkish it is et (using the English pronunciation). Also called as güzel a (beautiful a), özel a (special a), salyangoz (snail), koç (ram), kuyruklu a (a with tail) and çengelli a (a with hook).
- In Ukrainian it is commonly called et ("at"), other names being ravlyk (равлик) (snail), slymachok (слимачок) (little slug), vukho (вухо) (ear) and pesyk (песик) (little dog).
- In Vietnamese it is called a còng (bent a) in the North and a móc (hooked a) in the South.
- In Welsh it is sometimes known as a malwen or malwoden (a snail).