The Hashtag: Uncovering the Mysteries of the Icon Popularized by Twitter

The Hashtag: Uncovering the Mysteries of the Icon Popularized by Twitter

Eugenia Luchetta Published on 4/19/2024

The phrase “hashtag” seems almost archaic and disconnected from today’s social media language, to the extent that in Italian, “hashtag” commonly refers to the pervasive “#.” However, in reality, the hashtag, or the hash mark/symbol/key in English, is just one aspect of it.

In Italian, # is known by a somewhat outdated single term, but in English, this grid-like symbol is known by many names. It has also assumed various roles over the centuries, first in the Anglo-Saxon world and then globally. In Britain, it’s referred to as the hash symbol (originating from crosshatch), in America as the number sign or pound sign, and the technical term is octothorpe. This is complemented by a slew of informal names inspired by its appearance, like square, grid, fence, crunch, and more.

From left: Akzidenz Grotesk, Big Caslon and Fago. The gate does not show much variety in design among different typefaces. It almost never has any graces and what varies is only the slope and spacing of the rods, which are very often of equal thickness.

Tracing the historical names of the hash symbol is also tracing the various meanings it has acquired over time. One notable early usage is as the “pound sign.”

A Measure of Weight

The pound sign’s origins predate social networks and even telephones, tracing back to Latin. The precise origin of the symbol as we know it is unclear, but its derivation from the Latin term libra pondo, meaning “weight in pounds” (pound in English comes from pondo, meaning weight), is known. Abbreviated to lb since the 1300s, the English added a hyphen to symbolize contraction. By the 1600s, printers were producing movable type specifically for this glyph.

The transformation of the lb symbol into the hash mark as we recognize it today likely evolved through handwriting. The exact time when the current form became official is unclear, but it appears that the rapidly sketched lb morphed into #.

A detail from Johann Conrad Barchusen’s “Pyrosophia” (1698), which shows the symbol lb with a perpendicular hyphen as an indication of embraviation. Courtesy of the Roy G. Neville Historical Chemical Library, CHF.

Thus, the pound sign’s name and usage as a measurement unit emerged. This function also led to another American usage of # as the equivalent of “number,” still commonly used today as an abbreviation for “No.” or “№.”

The above stroke is the crossed-out “lb” symbol, drawn by Isaac Newton. Courtesy of the Chemical Heritage Foundation Collections

An Obscure Key (and Name)

Although not widely known and seldom used, the technical term for # in English is octothorpe. The origins of this bizarre and hard-to-pronounce word date back to the 1960s at Bell Laboratories. Researchers revamping the telephone keypad added two new keys next to the zero. The asterisk and hash mark, familiar to many from ASCII convention, were chosen. To avoid confusion with the British currency symbol also called pound, the # needed a distinct name. The term octothorpe was coined, with octo- indicating the symbol’s eight points and the second part of the word having unclear origins, leading to various anecdotes. The most accepted theory links it to Olympian Jim Thorpe, who was stripped of his medals for playing professional basketball. It seems the name was chosen by an employee who was a fan of Thorpe.

1966, 1500 series telephone model, Bell Labs. One of the first models to feature the “*” and “#” symbols.

The hash mark on telephone keypads was meant for specific commands, but like the name octothorpe, it remained largely unused by the general populace. The hashtag, devoid of any real meaning, became widely known to the public.

The Rise to Fame

Chris Messina, recognized as the inventor of the modern hashtag, gave # a significant role. A social networking and digital interaction expert, Messina proposed that Twitter adopt hashtags to group, categorize, and index discussions using a word preceded by #. Hashtags had already existed on the Internet in Internet Relay Chat (IRC), where users communicated in channels identified by a hashtag denoting the topic. It was in this community that the term “hashtag” was coined.

Twitter’s founders initially received Messina’s idea tepidly, considering it too “geeky.” However, hashtags began to gain traction within Twitter. In 2008, Obama’s election campaign launched the hashtag #askobama. In response, Twitter implemented hyperlink functionality in hashtags the following year, allowing for searchable tweets containing specific hashtags. Over the next three years, hashtag usage exploded across various platforms, including YouTube, Tumblr, LinkedIn,Instagram, and Facebook.

Hashtags revolutionized communication, particularly in marketing. Like other symbols [link article on the @], the birth of hashtags rejuvenated the #, transforming it into an ultra-recognizable and meaningful sign. As with the @, Messina chose # for its pre-existing status rather than creating something new, enhancing its understandability and adoption chances.

In a world of rapidly evolving technology that continually alters interaction methods and behaviors, it’s intriguing to ponder which other overlooked keyboard symbols might come alive and integrate into our daily lives.

Sources: Keith Houston. “Shady Characters: The Secret Life of Punctuation, Symbols, and Other Typographical Marks” (2013).