The Origins of Hashtags
The symbol itself - formally known as the Octothorpe but also called a number sign or pound sign, dates back to ancient Roman times. A New Yorker article called "The Ancient Roots of Punctuation" states:
"The story of the hashtag begins sometime around the fourteenth century, with the introduction of the Latin abbreviation “lb,” for the Roman term libra pondo, or 'pound weight.' Like many standard abbreviations of that period, “lb” was written with the addition of a horizontal bar, known as a tittle, or tilde... And though printers commonly cast this barred abbreviation as a single character, it was the rushed pens of scribes that eventually produced the symbol’s modern form: hurriedly dashed off again and again, the barred “lb” mutated into the abstract #... Though it is now referred to by a number of different names—“hash mark,” 'number sign,' and even 'octothorpe,' a jokey appellation coined by engineers working on the Touch-Tone telephone keypad—the phrase “pound sign” can be traced to the symbol’s ancient origins. For just as 'lb' came from libra, so the word 'pound' is descended from pondo, making the # a descendent of the Roman term libra pondo in both name and appearance."
The specific use of the symbol in a recognizable "hashtag" way is a lot older than you might think! A Lifewire article on the topic noted: "The metadata tags have been actually been around for quite some time, first being used in 1988 on a platform known as Internet Relay Chat or IRC. They were used much then as they are today, for grouping messages, images, content, and video into categories. The purpose of course, is so users can simply search hashtags and get all the relevant content associated with them." According to Lifewire, a resident of San Diego started using the hashtag #sandiegofire on Twitter (which launched July 15, 2006) to inform people about the ongoing wildfires in August 2007; other articles indicate that the first suggestion of # as a tracking tool to Twitter came from Chris Messina. This blog post by Stowe Boyd is believed to be the first one to actually coin the term "hashtag."
You can now use hashtags to track or group posts on a common theme on Twitter, Facebook, Instagram, or Pinterest. I'll admit that I mostly use them sarcastically (as in the above headline or in my commonly used #blessed), but I do actually use them on my personal Instagram to track my ongoing photo chronicling of all my nail polish shades via #naileditproject (however, you'd have to be friends with me to see those, so it's really for my own personal use rather than to commune with others).
