Name this symbol (#). Hashtag, obviously, or is it the pound sign? Maybe the number symbol? Depending on the context, all of these may be correct, but it may surprise you to learn that this symbol has an official name, octothorpe.

The symbol itself may be centuries old. Scribes and bookkeepers used to abbreviate “libra pondo,” or “pound in weight,” as lb with a line across the top (℔ ). Most sources say over time the quick scrawling of this abbreviation became the symbol we recognize today. The pound sign also came to represent “number” as in #2 pencil or Apt. #25. It was eventually included in its current form on typewriter keyboards which helped it to survive and grow in popularity and usage.

In 1963, the touch tone phone was invented, replacing rotary phones. Five years later Bell Laboratories added the asterisks (*) and the pound sign (#) to the phone key pad making it a neat 3 by 4 rectangle and to give two more options for the new phone menus that touch tone phones made possible. These symbols were chosen because they were already a part of the QWERTY keyboard and would be easily recognized by computers.

While trying to reference the symbol in manuals, Bell Lab employees realized that it did not have an official name, so they decided to give it one, “octo” for the eight points and “therp” which was just nonsense, possibly the sound of a burp. Later the name was changed from octotherp to octothorpe which may or may not have been a tribute to Olympic athlete Jim Thorpe, who had no known connection to the symbol.

In 2007, technology developer Chris Messina suggested another use for the octothorpe on the micro-blogging site formerly known as Twitter. He purposed using it as a way to tag posts for easier searching. A British term for the symbol, “hash,” combined with the idea of tagging posts created yet another name for the symbol, the hashtag. Hashtags have grown in popularity and are now widely used in marketing campaigns, political and social movements, and as a form of slang in everyday speech. While octothorpe may technically be the official name, people are far more likely to be calling it a hashtag for the foreseeable future unless perhaps someone wants to start a campaign on X for #octothorpeappreciation.

Crystal Kelly is a feature writer for Bizarre Bytes with those unusual facts that you only need to know for Trivial Pursuit or Jeopardy or to stump your in-laws.

Follow KnoxTNToday on Facebook and Instagram. Get all KnoxTNToday articles in one place with our Free Newsletter.