In this edition of “terms from the world of IT explained “, I will not talk about a term in particular, but about the history of a sign we all use daily: the at-sign or @. We use it in e-mail-addresses or on social media platforms for our handles, but why is it one of the most important symbols on the internet? You might think, that the @ is a child of the internet, but far from it! The earliest text it is used in is from the 14th century. In this blog post I would like to take you on a brief journey through time with the at-sign.
Our first stop is the Vatican Apostolic library in Rome. It holds a religious text from the 14th century, a Bulgarian translation of a Greek chronicle in which the @ is used instead of the capital letter alpha in the word “Amen”. However, it is still a mystery why it was used in this context.
An interesting theory about its origin is that medieval monks might have used it to abbreviate the Latin word “ad”, which means at. A reason for the abbreviation could have been that they copied thousands of pages of biblical manuscripts on expensive material like papyrus. In these copies, the word “ad” was used very often and resources could be spared by using an abbreviation.
The commercial history of the @-symbol is a lot clearer. The first documented commercial use was in 1536 in a letter from the Florentine merchant Francesco Lapi, who described units of wine (amphorae) with the symbol. In his letter, one @ equated to one unit of wine. Later, merchants used it to describe prices. It meant “at the rate of”, so 10 products @ 1 Euro, would mean that the total of 10 products costs 10 Euros.
But why is the @ included in our e-mail addresses? This goes back to the computer scientist Ray Tomlinson, who used it in 1971 when he worked on the Arpanet, a forerunner of the Internet. He had to find a symbol to address a message created by one person and send through Arpanet to someone at a different computer. In order not to confuse computers, it had to be a sign that was not used much. He then saw the @ on a Model 33 teletype. Using his new naming system he sent an e-mail to himself. It travelled from one teletype to another in the same office – but through Arpanet. With this invention Tomlinson turned a nearly forgotten symbol into one of the most used ones in modern digital life.