At sign

Theat sign,@, is anaccountingandinvoiceabbreviation meaning "at a rate of" (e.g. 7widgets@£2 per widget = £14),now seen more widely inemailaddresses andsocial mediaplatformhandles. It is normally read aloud as "at" and is also commonly called theat symbol,commercial at, oraddress sign.
The absence of a single English word for the symbol has prompted some writers to use theFrencharobase,OccitanarròbaandAragonese,Catalan,PortugueseandSpanisharroba, or to coin new words such asampersatandasperand,or the (visual) onomatopoeiastrudel,but none of these have achieved wide use.
Although not included on the keyboard of the earliest commercially successfultypewriters, it was on at least one 1889 modeland the very successfulUnderwoodmodels from the "Underwood No. 5" in 1900 onward. It started to be used in email addresses in the 1970s, and is now routinely included on most types ofcomputer keyboards.
The earliest yet discovered symbol in this shape is found in aBulgariantranslation of aGreekchronicle written byConstantinos Manassesin 1345. Held today in the Vatican Apostolic Library, it features the @ symbol in place of the capital letteralpha"Α" as aninitialin the word Amen; however, the reason behind it being used in this context is still unknown. The evolution of the symbol as used today is not recorded.
It has long been used inCatalan,SpanishandPortugueseas an abbreviation ofarroba, a unit of weight equivalent to 25 pounds, and derived from theArabicexpression of "the quarter" (الربعpronouncedar-rubʿ).A symbol resembling an @ is found in the Spanish "Taula de Ariza", a registry to denote a wheat shipment from Castile to Aragon, in 1448.The historian Giorgio Stabile claims to have traced the @ symbol to the 16th century, in a mercantile document sent byFlorentineFrancesco Lapi fromSevilletoRomeon May 4, 1536.The document is about commerce withPizarro, in particular the price of an @ of wine inPeru. Currently, the wordarrobameans both the at-symbol and a unit of weight. InVenetian, the symbol was interpreted to meanamphora(anfora), a unit of weight and volume based upon the capacity of the standard amphora jar since the 6th century. It could also mean “adi” (standard Italian “addì”, i. e. ‘on the day of’) as used on a health pass in Northern Italy in 1667.
In contemporary English usage, @ is a commercial symbol, meaningatandat the rate oforat the price of. It has rarely been used in financial ledgers, and is not used in standardtypography.
In 2012, "@" was registered as atrademarkwith the German Patent and Trade Mark Office.A cancellation request was filed in 2013, and the cancellation was ultimately confirmed by the German Federal Patent Court in 2017.
A common contemporary use of @ is inemail addresses(using theSMTPsystem), as injdoe@example.com(the userjdoelocatedatthe domainexample.com).Ray TomlinsonofBBN Technologiesis credited for having introduced this usage in 1971.This idea of the symbol representinglocated atin the formuser@hostis also seen in other tools and protocols; for example, theUnix shellcommandssh jdoe@example.nettries to establish ansshconnection to the computer with thehostnameexample.netusing the usernamejdoe.
On web pages, organizations often obscure the email addresses of their members or employees by omitting the @. This practice, known asaddress munging, attempts to make the email addresses less vulnerable to spam programs that scan the internet for them.
On some social media platforms and forums, usernames may be prefixed with an @ (in the form@johndoe); this type of username is frequently referred to as a "handle".
On online forums withoutthreaded discussions, @ is commonly used to denote a reply; for instance:@Janeto 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@Keirstento indicate to Keirsten that the following sentence concerns her.This also helps with mobile email users who might not see bold or color in email.
Inmicroblogging(such as onTwitter,GNU social- andActivityPub-based microblogs), an @ 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 handle. A similar use of the @ symbol was also made available to Facebook users on September 15, 2009.InInternet Relay Chat(IRC), it is shown before users' nicknames to denote they have operator status on a channel.
InAmerican Englishthe @ can be used to add information about a sporting event. Where opposing sports teams have their names separated by a "v" (forversus), theaway teamcan be written first – and the normal "v" replaced with @ to convey at which team's home field the game will be played.This usage is not followed inBritish English, since conventionally the home team is written first.
@ is used in variousprogramming languagesand othercomputer languages, although there is not a consistent theme to its usage. For example:
InSpanish, where many words end in "-o" when in the masculinegenderand end "-a" in the feminine, @ is sometimes used as agender-neutralsubstitute for the default "o" ending.For example, the wordamigostraditionally represents not only male friends, but also a mixed group, or where the genders are not known. The proponents of gender-inclusive language would replace it withamig@sin these latter two cases, and useamigosonly when the group referred to is all-male andamigasonly when the group is all female. TheReal Academia Españoladisapproves of this usage.
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. Naming the symbol after animals is also common.
In Unicode, the at sign is encoded asU+0040@COMMERCIAL AT(&commat;). The named entity&commat;was introduced in HTML5.