At sign

@
At sign

The at sign, @, normally read aloud as "at", also commonly called the at symbol or commercial at, is originally an accounting and commercial invoice abbreviation meaning "at a rate of" (e.g. 7 widgets @ £2 = £14). In contemporary use, the at-sign is most commonly used in email addresses. It was not included on the keyboard of the earliest commercially successful typewriters, but was on at least one 1889 model^[1] and the very successful Underwood models from the "Underwood No. 5" in 1900 onward. It is now universally included on computer keyboards. The mark is encoded at U+0040 @ COMMERCIAL AT (HTML @).

The fact that there is no single word in English for the symbol has prompted some writers to use the French arobase^[2] or Spanish and Portuguese arroba, or to coin new words such as asperand,^[3] ampersat^[4] and strudel^[5]), but none of these have achieved wide usage.

History

Origin theories

@ symbol used as the initial "a" for the "amin" (amen) formula in the Bulgarian translation of the Manasses Chronicle (c. 1345).

The Aragonese @ symbol used in the 1448 "taula de Ariza" registry to denote a wheat shipment from Castile to the Kingdom of Aragon.^[6]

@ used to signify French "à" ("at") from a 1674 protocol from a Swedish court (Arboga rådhusrätt och magistrat)

The earliest yet discovered reference to the @ symbol is a religious one; it features in a Bulgarian translation of a Greek chronicle written by Constantinos Manasses in 1345 (See Figure left). Held today in the Vatican Apostolic Library,^[7] it features the @ symbol in place of the capital letter alpha 'A' in the word Amen. Why it was used in this context is still a mystery.

In terms of the commercial character of the at sign, there are several theories pending verification.

• One theory is that 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 at $1" would be $1—a crucial and necessary distinction.
• Another theory is that medieval monks abbreviated the Latin word ad (at, toward, by, about) next to a numeral. One reason for this abbreviation was that it saved space and ink. Since thousands of pages of biblical manuscripts were copied onto expensive papyrus or hides, and the words at, toward, by and about repeated millions of times throughout the pages, a considerable amount of resources could be spared this way. A theory concerning this graphic puts forward the idea that the form derives from the Latin word ad,, using the older form of lower case d : ∂, which persists as the partial derivative symbol.
• It has been theorized that it was originally an abbreviation of the Greek preposition ανά (transliterated ana), meaning at the rate of or per.
• Another theory is that it derives from the Norman French "à" meaning "at" in the "each" sense, i.e. "2 widgets à £5.50 = £11.00", comes the accountancy shorthand notation in English commercial vouchers and ledgers to the 1990s, when the email usage overtook the accountancy usage. It is also used like this in Modern French, Swedish or Czech; 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 found in street market signs.

History

Whatever the origin of the @ symbol, the history of its usage is more well-known: it has long been used in Spanish and Portuguese as an abbreviation of arroba, a unit of weight equivalent to 25 pounds, and derived from the Arabic expression of "a quarter" (الربع pronounced ar-rubʿ).^[8] An Italian academic claims to have traced the @ symbol to the 16th century, in a mercantile document sent by Florentine Francesco Lapi from Seville to Rome on May 4, 1536.^[9] The document is about commerce with Pizarro, in particular the price of an @ of wine in Peru. In Italian, the symbol was interpreted to mean amphora (anfora). Currently, the word arroba means both the at-symbol and a unit of weight. In Italian, the symbol represents one amphora, a unit of weight and volume based upon the capacity of the standard amphora jar, and entered modern meaning and use as "at the rate of" or "at price of" in northern Europe.

Until now the first historical document containing a symbol resembling a @ as a commercial one is the Spanish "Taula de Ariza", a registry to denote a wheat shipment from Castile to Aragon in 1448. Even though the oldest fully developed modern @ sign is the one found on the above-mentioned Florentine letter.^[9]

Modern use

Commercial usage

In contemporary English usage, @ is a commercial symbol, called at site or at rate meaning at and at the rate of. It has rarely been used in financial documents or grocers' price tags, and is not used in standard typography.^[10]

Since 23 October 2012, the At-sign is registered as a trade mark by the German Patent and Trade Mark Office – DPMA (registration number 302012038338) for @T.E.L.L. While company promoters have claimed that it may from now on be illegal for other commercial interests to use the At-sign, this only applies to identical or confusingly similar goods ^[11] and no court, German or otherwise, has yet ruled on this purported illegality.

Contemporary usage

A common contemporary use of @ is in email addresses (using the SMTP system), as in [e-mail] (the user jdoe located at site the example.com domain). BBN Technologies' Ray Tomlinson is credited with introducing this usage in 1971.^[12] This idea of the symbol representing located at in the form user@host is also seen in other tools and protocols; for example, the Unix shell command ssh [e-mail] tries to establish an ssh connection to the computer with the hostname example.net using the username jdoe.

On web pages, organizations often obscure email addresses of their members or employees by omitting the @. This practice, known as address munging, makes the email addresses less vulnerable to spam programs that scan the internet for them.

Another contemporary use of the @ symbol in American English is adding information about a sporting event. Opposing sports teams sometimes have their names separated by a v. (for versus). However, the "v." may be replaced with "@" when also conveying at which team's home field the game will be played. In this case, the away team is written first.^[13] This usage is not followed in British English, since conventionally the home team is written first.

On some online forums without threaded discussions, @ is used to denote a reply; for instance: "@Jane" to respond to a comment Jane made earlier. Similarly, in some cases, @ is used for "attention" in email messages originally sent to someone else. For example, if an 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 cannot see bold or color in email.

In microblogging (such as Twitter and StatusNet-based microblogs), @ before the user name is used to send publicly readable replies (e.g. "@otheruser: Message text here"). The blog and client software can automatically interpret these as links to the user in question. When included as part of a person's or company's contact details, an @ symbol followed by a name is normally understood to refer to a Twitter ID. A similar use of the @ symbol was also made available to Facebook users on September 15, 2009.^[14] In Internet Relay Chat (IRC), it is shown before users' nicks to denote they have operator status on a channel.

Programming

@ is used in various programming languages although there is not a consistent theme to its usage. For example:

• In ALGOL 68, the @ symbol is brief form of the at keyword; it is used to change the lower bound of an array. For example: arrayx[@88] now refers to an array starting at index 88.
• In ActionScript, @ is used in XML parsing and traversal as a string prefix to identify attributes in contrast to child elements.
• In CSS, @ is used in special statements outside of a CSS block.
• In C#, it denotes "verbatim strings", where no characters are escaped and two double-quote characters represent a single double-quote.^[15] As a prefix it also allows keywords to be used as identifiers,^[16] a form of stropping.
• In the ASP.NET MVC Razor template markup syntax, the @ character denotes the start of code statement blocks or the start of text content.^[17][18]
• In Forth, it is used to fetch values from the address on the top of the stack. The operator is pronounced as "fetch".
• In Haskell, it is used in so-called as-patterns. This notation can be used to give aliases to patterns, making them more readable.
• In Java, it has been used to denote annotations, a kind of metadata, since version 5.0.
• In LiveCode, it is prefixed to a parameter to indicate that the parameter is passed by reference.
• In ML, it denotes list concatenation.
• 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').
• In Objective-C, @ is prefixed to language-specific keywords such as @implementation and to form string literals.
• In Pascal, @ is the "address of" operator (it tells the location at which a variable is found).
• In Perl, @ prefixes variables which contain arrays @array, including array slices @array[2..5,7,9] and hash slices @hash{'foo', 'bar', 'baz'} or @hash{qw(foo bar baz)}. This use is known as a sigil.
• In PHP, it is used just before an expression to make the interpreter suppress errors that would be generated from that expression.^[19]
• In Python 2.4 and up, it is used to decorate a function (wrap the function in another one at creation time).
• In Ruby, it functions as a sigil: @ prefixes instance variables, and @@ prefixes class variables.
• In Scala, it is used to denote annotations (as in Java), and also to bind names to subpatterns in pattern-matching expressions.
• In Swift, @ prefixes "annotations" that can be applied to classes or members. Annotations tell the compiler to apply special semantics to the declaration like keywords, without adding keywords to the language.
• In T-SQL, @ prefixes variables.
• In several xBase-type programming languages, like DBASE, FoxPro/Visual FoxPro and Clipper, it is used to denote position on the screen. For example: @1,1 SAY "HELLO" to show the word "HELLO" in line 1, column 1.
• In FoxPro/Visual FoxPro, it is also used to indicate explicit pass by reference of variables when calling procedures or functions (but it is not an address operator).^[20]
• In Windows PowerShell, @ is used as array operator for array and hash table literals and for enclosing here-string literals.^[21]
• In the Domain Name System, @ is used to represent the $ORIGIN, typically the "root" of the domain without a prefixed sub-domain. (Ex: wikipedia.org vs. www.wikipedia.org)

Gender-neutrality in Spanish and Portuguese

In Portuguese and Spanish, as well in other West Iberian languages where many words end in '-o' when in the masculine gender and end '-a' in the feminine, @ is sometimes used as a gender-neutral substitute for the default 'o' ending,^[22] which some advocates of gender-neutral language-modification feel indicates implicit linguistic disregard for women. These languages do not possess a neutral gender and the masculine forms are also used traditionally when referring to groups of mixed or unknown sex. The at-sign is intended to replace the desinence '-o', including its plural form '-os', due to the resemblance to a digraph of an inner letter 'a' and an outer letter 'o'.

As an example of the @ being used for gender-inclusive purposes, we can consider the Spanish and Portuguese word amigos. When the word represents not only male friends, but also female ones, the proponents of a gender-inclusive language replace it with amig@s. In this sense, amigos would be used only when the writer is sure the group referred to is all-male. Usage of amigas is the same in traditional and such new forms of communication. Alternative forms for a gender-inclusive at-sign would be the slash sign (amigos/as) and the circle-A, (amigⒶs). However, it is more common to use the masculine ending first and include the feminine in parentheses, as in amigos(as). For more about this, see Satiric misspelling. Lately, though, it's becoming more and more common (since slashes and parentheses put first the masculine form and the other two are seen as "an 'a' inside an 'o'", meaning, in their eyes, that the feminine is supedited to the masculine) the use of the 'x' letter instead, a use that is the choice of advocates of gender-inclusive language, but strongly frowned upon by people not adhered to said movement (but not necessarily against it). The Real Academia Española disapproves of the use of the at-sign as a letter.^[23]

Other uses and meanings

• In (especially English) scientific and technical literature, @ is 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).
• As an abbreviation for alias in articles about missing persons, obituaries, brief reports - for instance: "John Smith @ Jean Smyth" (a possible abbreviation of aka). For example, a Chinese Singaporean may use two transliterations of his or her Chinese name (e.g., Mao Tse-Tung @ Mao Zedong).
• In chemical formulae, @ is used to denote trapped atoms or molecules. For instance, La@C₆₀ means lanthanum inside a fullerene cage. See article Endohedral fullerene for details.
• In Malagasy, @ is an informal abbreviation for the prepositional form amin'ny.
• In genetics, @ is the abbreviation for locus, as in IGL@ for immunoglobulin lambda locus.
• In the Koalib language of Sudan, @ is used as a letter in Arabic loanwords. The Unicode Consortium rejected a proposal to encode it separately as a letter in Unicode, but SIL International uses Private Use Area code points U+F247 and U+F248 for lowercase and capital versions.^[24]
• A schwa, as the actual schwa character "ə" may be difficult to produce on many computers. It is used in this capacity in the ASCII IPA schemes SAMPA, X-SAMPA and Kirshenbaum.
• In leet it may substitute for the letter "A".
• It is frequently used in typing and text messaging as an abbreviation for "at".
• In Portugal it may be used in typing and text messaging with the meaning "french kiss" (linguado).
• In online discourse, @ is used by some anarchists as a substitute for the traditional circle-A.
• An abbreviation for "around"

Names in other languages

In many languages other than English, although most typewriters included the symbol, the use of @ was less common before email became widespread in the mid-1990s. Consequently, it is often perceived in those languages as denoting "the Internet", computerization, or modernization in general.

• In Afrikaans, it is called aapstert, meaning "monkey tail", similarly to the Dutch use of the word.
• In Arabic, it is آتْ (at).
• In Armenian, it is շնիկ (shnik), which means "puppy".
• In Azeri, it is ət (at), which means "dog".
• In Basque, it is a bildua ("wrapped A").
• In Belarusian, it is called сьлімак (ślimak, meaning "helix" or "snail").
• In Bosnian, it is ludo a ("crazy A").
• In Bulgarian, it is called кльомба (klyomba – "a badly written letter"), маймунско а (maymunsko a – "monkey A"), маймунка (maimunka – "little monkey"), or баница ("banitsa" - a pastry roll often made in a shape similar to the character)
• In Catalan, it is called arrova ("a unit of measure") or ensaïmada (because of the similar shape of this food).
• In Chinese:
  • In mainland China, it used to be called 圈A (pronounced quān A), meaning "circled A / enclosed A", or 花A (pronounced huā A), meaning "lacy A", and sometimes as 小老鼠 (pronounced xiǎo lǎoshǔ), meaning "little mouse".^[25] Nowadays, for most of China's youth, it is called 艾特 (pronounced ài tè), which is the phonetic transcription from "at".
  • In Taiwan, it is 小老鼠 (pronounced xiǎo lǎoshǔ), meaning "little mouse".
  • In Hong Kong and Macau, it is at.
• In Croatian, it is most often referred to by the English word "at". Informally, it is called a manki, coming from the local pronunciation of the English word "monkey". Note that the Croatian word for monkey, majmun, is not used to denote the symbol.
• In Czech and Slovak, it is called zavináč, which means "rollmops".
• In Danish, it is snabel-a ("elephant's trunk A"). It is not used for prices, where in Danish a alone means at (per piece).
• In Dutch, it is called apenstaartje ("[little] monkey tail"). The "a" is the first character of the Dutch word "aap" which means "monkey". However, the use of the English ´at´ has been coming increasingly popular in Dutch.
• In Esperanto, it is called ĉe-signo ("at" – for the email use, with an address like "[e-mail]" pronounced zamenhof ĉe esperanto punkto org), po-signo ("each" – refers only to the mathematical use), or heliko (meaning "snail").
• In Estonian, it is called ätt, from the English word "at".
• In Faroese, it is kurla, hjá ("at"), tranta, or snápil-a ("[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 ("miaow-meow").
• In French, it is now officially the arobase^[26][27] (also spelled arrobase 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 email address). Its origin is the same as that of the Spanish word, which could be derived from the Arabic ar-roub. In France, it is also common (especially for younger generations) to say the English word "at" when spelling out an email address. In everyday Québec French, one often hears a commercial when sounding out an e-mail address, while TV and radio hosts are more likely to use arobase.
• In Georgian, it is at, spelled ეთ–ი (კომერციული ეთ–ი).
• In German, it has sometimes been referred to as Klammeraffe (meaning "spider monkey") or Affenschwanz. Klammeraffe or Affenschwanz refer to the similarity of @ to the tail of a monkey grabbing a branch. Lately, it has mostly been called at, just like in English.
• In Greek, it is most often referred to as παπάκι (papaki), meaning "duckling", due to the similarity it bears with comic character designs for ducks.
• In Greenlandic, and Inuit language, it is called aajusaq meaning "A-like" or "something that looks like A".
• In Hebrew, it is colloquially known as שטרודל (shtrudel), due to the visual resemblance to a cross-section cut of a strudel cake. The normative term, invented by The Academy of the Hebrew Language, is כרוכית (krukhit), which is another Hebrew word for "strudel", but is rarely used.
• In Hindi, it is at, from the English word.
• In Hungarian, it is called kukac (a playful synonym for "worm" or "maggot").
• In Icelandic, it is referred to as atmerkið ("the at sign") or hjá, which is a direct translation of the English word "at".
• In Indian English, speakers often say at the rate of (with e-mail addresses quoted as "example at the rate of example.com").
• In Indonesian, it is usually et. Variations exist – especially if verbal communication is very noisy – such as a bundar and a bulat (both meaning "circled A"), a keong ("snail A"), and (most rarely) a monyet ("monkey A").
• In Irish, it is ag (meaning "at") or comhartha @/ag (meaning "at sign").
• In Italian, it is chiocciola ("snail") or a commerciale, sometimes at (pronounced more often [ˈɛt] and rarely [ˈat]) or ad.
• In Japanese, it is called attomāku (アットマーク, from the English words "at mark"). The word is wasei-eigo, a loan word from the English language. It is sometimes called Naruto, because of Naruto whirlpools or food (Narutomaki).
• 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, meaning "bai top shells"), a dialectal form of whelk.
• In Kurdish, it is ئه ت at, from the English word.
• In Kyrgyz, it is officially called маймылча ("monkey"), sometimes unofficially as собачка ("doggy"), and et.
• In Latvian, it is pronounced the same as in English, but, since in Latvian [æ] is written as "e" (not "a" as in English), it is sometimes written as et.
• In Lithuanian, it is et (equivalent to the English "at").
• In Luxembourgish it used to be called Afeschwanz ("monkey tail"), but due to widespread use, it is now called at, as in English.
• In Macedonian, it is called мајмунче (my-moon-cheh – "little monkey").
• In Malay, it is called alias when it is used in names and di when it is used in email addresses. It is also commonly used to abbreviate atau which means "or" or "either".
• In Morse code (not a language), it is known as a "commat", consisting of the Morse code for the "A" and "C" which run together as one character: ·--·-·. The symbol was added in 2004 for use with email addresses,^[28] the only official change to Morse code since World War I.
• In Norwegian, it is officially called krøllalfa ("curly alpha" or "alpha twirl"). (The alternate alfakrøll is also common, but is not its official name.) Sometimes snabel-a, the Swedish/Danish name (which means "trunk A", as in "elephant's trunk"), is used. Commonly, people will call the symbol [æt] (as in English), particularly when giving their email addresses.
• In Persian, it is at, from the English word.
• In Polish, it is called, both officially and commonly, małpa ("monkey"), and sometimes małpka ("little monkey").
• In Portuguese, it is called arroba (from the Arabic arrub). The word "arroba" is also used for a weight measure in Portuguese. One arroba is equivalent to 32 old Portuguese pounds, approximately 14.7 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 used to represent the same measure.)
• In Romanian, it is most commonly called at, but also colloquially called Coadă de maimuţă ("monkey tail") or a-rond. The latter is commonly used, and it comes from the word "round" (from its shape), but that is nothing like the mathematical symbol A-rond (rounded A). Others call it aron, or la (Romanian word for at).

@ on a DVK Soviet computer (c. 1984)

• In Russian, it is most commonly собака (sobaka, meaning "dog"). The name "dog" has come from Soviet computers DVK where the symbol had a short tail and similarity to a dog.
• In Serbian, it is called лудо А (ludo A – "crazy A"), мајмунче (majmunče – "little monkey"), or мајмун (majmun – "monkey").
• In Slovak, it is called zavináč ("pickled fish roll", as in Czech).
• In Slovenian, it is called afna ("monkey" (informally)).
• 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.
• In Swedish, it is called snabel-a ("elephant's trunk A") or simply at, as in the English language. Less formally it is also known as kanelbulle ("cinnamon roll") or alfakrull ("alpha curl").
• In Swiss German, it is commonly called Affenschwanz ("monkey-tail"). However, the use of the English ´at´ has been coming increasingly popular in German.
• In Tagalog, the word at means "and"; the symbol is thus used like an ampersand in colloquial writing such as text messages (e.g. magluto @ kumain, "cook and eat").
• In Thai, it is commonly called at, as in English.
• In Turkish, it is commonly called et, like in English but written in Turkish letters.
• In Ukrainian, it is commonly called ет (et – "at"), other names being равлик (ravlyk – "snail"), слимачок (slymachok – "little slug"), вухо (vukho – "ear"), and песик (pesyk – "little dog").
• In Urdu, it is اٹ (at).
• In Uzbek, it is called kuchukcha, which loosely means "doggy"—a direct calque from Russian.
• 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 (both meaning "snail").

Unicode variants

• U+0040 @ REGULAR COMMERCIAL AT (HTML @)
• U+FF20 ＠ FULL-WIDTH COMMERCIAL AT (HTML ＠)
• U+FE6B ﹫ SMALL COMMERCIAL AT (HTML ﹫)

In culture

In roguelike video games such as Brogue, whose graphics are composed of ASCII characters, the player is represented by @.

• The Museum of Modern Art admitted the at sign to its architecture and design collection.^[25]
• Author Philip Pullman added the category of "things that were invented for one purpose, but are used for another" to his "Museum of Curiosity" collection with the @ as an example.^[29]
• John Lloyd, pledged on QI series A DVD to support widespread use of the term "Astatine" to refer to the symbol. This name was chosen as the chemical element astatine has the chemical symbol "At".^[30]
• American R&B singer Usher used a version of the at sign in his career, where the "a" was replaced with the vowel "u" from his name. Puerto Rican artist Miguelito also uses his version of the at sign where the "a" is replaced by the letter "m" from his name in his own line of merchandise that includes clothes, school supplies, his studio albums, etc.
• A Chinese couple tried to name their son @—pronouncing it "ai ta" or "love him"—according to the Chinese State Language Commission.^[31][32]
• In the 1980 video game Rogue, presented in ASCII graphics, the player character is represented by the @. Many similar games, called Roguelikes, use the same presentation, and traditionally use the @ to represent the player character as well.

See also

• Circle-A
• Enclosed A (Ⓐ, ⓐ)
• ASCII
• Unicode

References

1. "The @-symbol, part 2 of 2", Shady Characters ⌂ The secret life of punctuation
2. "Short Cuts", Daniel Soar, Vol. 31 No. 10 · 28 May 2009 page 18, London Review of Books
3. "New York's Moma claims @ as a design classic", Jemima Kiss, 28 March 2010, The Observer
4. "… Tim Gowens offered the highly logical "ampersat" …", 05 February 1996, The Independent
5. "strudel". FOLDOC. Retrieved 2014-11-21.
6. "La arroba no es de Sevilla (ni de Italia)". purnas.com. Jorge Romance. Retrieved 2009-06-30.
7. "Chronicle of Constantinus Manasses". www.worldcat.org. Retrieved 2016-03-08.
8. "arroba". Diccionario de la Real Academia Española. Retrieved 3 August 2012.
9. Willan, Philip (2000-07-31). "Merchant@Florence Wrote It First 500 Years Ago". The Guardian (London). Retrieved 2010-04-25.
10. Bringhurst, Robert (2002). The Elements of Typographic Style (version 2.5), p.272. Vancouver: Hartley & Marks. ISBN 0-88179-133-4.
11. Article 5 Trade Marks Directive, as interpreted in Case C-251/95 Sabel BV v Puma AG [1997] ECR I-6191
12. "The First Email".
13. For an example, see: http://www.nfl.com/schedules
14. "Tag Friends in Your Status and Posts - Facebook Blog".
15. 2.4.4.5 String literals,
16. "2.4.2 Identifiers".
17. Phil Haack. "Razor syntax quick reference".
18. ASP.NET MVC 3: Razor’s @: and <text> syntax
19. PHP: Error Control Operators – Manual
20. "Visual FoxPro Programming Language Online Help: SET UDFPARMS (Command), or MSDN Library 'How to: Pass Data to Parameters by Reference'.". Microsoft, Inc. Retrieved 2011-02-19.
21. "Windows PowerShell Language Specification 3.0 (PDF)".
22. Martell-Otero, Loida (Fall 2009). "Doctoral Studies as Llamamiento, or How We All Need to be 'Ugly Betty'". Perspectivas: 84–106.
23. DPD 1ͺ ediciσn, 2ͺ tirada
24. Constable, Peter, and Lorna A. Priest (October 12, 2009) SIL Corporate PUA Assignments 5.2a. SIL International. pp. 59-60. Retrieved on April 12, 2010.
25. "Why @ Is Held in Such High Design Esteem". The New York Times, Alice Rawsthorn, March 21, 2010. 2010-03-22. Archived from the original on 24 March 2010. Retrieved 2010-04-25.
26. "At last, France has a name for the @ sign", December 9, 2002, iol.co.za
27. Orthographe fixée par la Commission générale de terminologie et de néologie (Journal officiel du 8 décembre 2002)
28. "The ARRL Letter", Vol. 23, No. 18, April 30, 2004
29. "Meeting Twelve – P-51 Mustang, Tempting Fate, Inventions Being Used for Things They Weren't Designed For". The Museum of Curiosity. Season 2. Episode 6. 8 June 2009.
30. John Lloyd and John Mitchinson (6 November 2006). QI – The Complete First Series: "Factoids" (Audio Commentary) (DVD). BBC and 2 Entertain. OCLC 271537078. UPC 5014503232528.
31. "English invades Chinese language", August 17, 2007", People's Daily Online
32. "Couple try to name baby @", August 17, 2007, NZ Herald

External links

• commercial-at at the Free On-line Dictionary of Computing
• "The Accidental History of the @ Symbol ", Smithsonian magazine, September 2012, Retrieved June 2013.
• The @-symbol, part 1, intermission, part 2, addenda, Shady Characters ⌂ The secret life of punctuation August 2011, Retrieved June 2013.
• "Daniel Soar on @", London Review of Books, Vol. 31 No. 10, 28 May 2009, Retrieved June 2013.
• ascii64 – the @ book – free download (creative commons) – by patrik sneyd – foreword by luigi colani) November 2006, Retrieved June 2013.
• A Natural History of the @ Sign The many names of the at sign in various languages, 1997, Retrieved June 2013.
• Sum: the @ Symbol, LINGUIST List 7.968 July 1996, Retrieved June 2013.
• Where it's At: names for a common symbol World Wide Words August 1996, Retrieved June 2013.
• UK Telegraph Article: Chinese parents choose to name their baby "@" August 2007, Retrieved June 2013.
• Tom Chatfield tells the story of the @ sign on Medium