Any modern art gallery worth its salt is periodically required to raise a hue and cry with some new acquisition, to provoke a chorus of bemused or angry onlookers to exclaim: "But is it art?" By that token, the Museum of Modern Art in Manhattan just put itself back at the top of the big league. It has announced to the world that it has "acquired" the @ sign, and will "exhibit" it as a symbol of our relationships and communications with others in the digital world. The requirement for inverted commas is telling. The symbol is, of course, not owned by anyone from whom the museum could acquire it, and MoMa's curators haven't yet begun to work out if and how they will give it physical form.
The museum acknowledges this is the first time that it has acquired something that "cannot be had".
If there might have been bafflement in the general population, then MoMa's move sparked a firestorm of debate in the design world, with experts dismissing the move as a stunt, or worse, demeaning to real designers who design real new versions of the @ for fonts. Others, though, saw MoMa reinventing its design gallery for a new, virtual world, where so much exists only intangibly on the internet.
And at the centre of the storm is a momentous day in 1971 when a Boston computer programmer called Ray Tomlinson sent the world's first email. It was Mr Tomlinson who chose to use an otherwise obscure character to separate a recipient's name from the computer they used. MoMa credited Mr Tomlinson with being the (unintended) designer of the modern @.
"The appropriation and reuse of a pre-existing, even ancient symbol – a symbol already available on the keyboard yet vastly under-utilised, a ligature meant to resolve a functional issue (excessively long and convoluted programming language) brought on by a revolutionary technological innovation (the internet) – is by all means an act of design of extraordinary elegance and economy," said Paola Antonelli, MoMa's curator for architecture and design, answering the question: "But is it design?".
Unconvincing, counters Mike Essl, design professor at The Cooper Union, one of New York's most prestigious art schools. "I think it is conceptually light. It's like putting in the letter A. I think that certain typefaces render the @ sign particularly sexy, but I saw this and rolled my eyes. It has the advantage for MoMa of being a recession-proof acquisition. But I'm not going to go to MoMa to see the @ sign."
Steve Kennedy, adjunct professor of typography at the New School, was another expressing puzzlement – and finding it rather hard to take seriously. "What will it lead to?" he asked. "Maybe we will wake up tomorrow and discover that the Guggenheim has acquired the ampersand, and then there will be a big rush for the exclamation mark and the question mark. Maybe", he added, referring to the combination of the two, "someone will even acquire the terrabang?!"
But MoMa is deadly serious – and dead right to be moving in a radical new direction, says Alice Twemlow, chairman of the design criticism department at the School of Visual Art in New York. She calls the announcement a bold move, even era-defining, the equivalent of the same museum's 1934 design exhibition Machine Art, when it shocked the public by displaying for the first time in a gallery space the simple self-adjusting ball bearing, as an emblem of the machine age.
"That is now one of the iconic images from MoMa's history," says Ms Twemlow. "The acquisition of the @ sign might seem perplexing today, and yet in the future be seen as a perfect reflection of communications in 2010. They are moving design objects off the white plinth, where they tend to be held up as God-like items in a stark white environment. By pointing out something in the mess of current use, this is doing something new for a venerable old institution."
In the official blog post announcing the decision to add the @ symbol to the collection, Ms Antonelli declared a new world of possibilities. "It relies on the assumption that physical possession of an object as a requirement for an acquisition is no longer necessary."
She called it the only "free" piece in the collection, if not the only "priceless" one, and promised that it would be displayed in various typefaces, with the font listed as if it were the materials used in a piece by a sculptor or painter.
There's no official history of the @ symbol, and no real agreement on what to call it, either. It is known variously as the "at sign", a monkey's tail or the "sign of the meow". While some linguists believe it was first used in the fifth or sixth century to fuse the Latin words for "at" and "towards" together in a single symbol, it has also been used a unit of measurement before turning up as an accounting term, as in "3 @ £2".
For something so intangible, the @ sign is firmly ubiquitous, part of an estimated 200 billion emails sent every day and a signifier of all parts of our digital lives.
Tobias Frere-Jones, principal at the font design studio Hoefler & Frere-Jones, for one, loves it. "It is definitely a crowd-pleaser, in terms of rendering. In the pre-email days, it was part of a second class of characters, along with the asterisk, the % sign, and copyright and trademark symbols – not important enough to draw each time for each new font."
Now, he says, it poses a unique challenge. "When this one obscure symbol suddenly came to centre stage, people found it a generic, Helvetica-looking thing, so for me and other designers, it became a point of pride to design an @ sign that was specifically suited to each new font family. There's not much else in a typeface that goes to the same level of complexity as the @ sign."
Brief history of the @: A sign of the times
1448 In one reputed early use, the @ symbol appears before a wheat shipment from Castile to Aragon.
1885 The first typewriter includes the still-obscure sign, mainly used by accountants to denote cost per item.
1971 The first email, sent by American programmer Raymond Tomlinson, uses the symbol to indicate the recipient's location.
2010 With an estimated 210bn emails sent per day and many other uses besides, the @ sign is one of the most ubiquitous pieces of punctuation in the world.