Twitter is marking ten years since the hashtag was first used on the social media site by celebrating some of the most memorable uses of the digital symbol.
Former Google and Uber engineer Chris Messina first used the symbol as a way of tagging or categorising a tweet on August 23 2007, when he suggested the symbol could be used to create group messages.
"How do you feel about using # (pound) for groups. As in #barcamp [msg]? (sic)", he wrote.
Since then, the hashtag symbol has grown to become one of the most widely used and recognisable characters of the digital age, spreading across different social and online platforms.
Social movements and news events such as Black Lives Matter and the Ice Bucket Challenge have come to prominence partly through the use of their hashtags on social networks.
Support for victims in the wake of tragedy has also been a prominent use for the symbol, including #jesuischarlie in the aftermath of the attack on satirical magazine Charlie Hebdo, and #PutYourBatsOut in tribute to late Australian cricketer Phillip Hughes.
Such is its commonplace that many television shows now flash a related hashtag on screen during their programmes to direct viewers towards online conversation.
According to Twitter, the most used hashtag in 2007 - #noticias, the Spanish word for news - was tweeted around 9,000 times.
In contrast, the biggest of 2017 has already been used more than 300 million times, the social media site said.
The hashtag in question, #BTSBBMMAS, refers to K-Pop band BTS and their victory at this year's Billboard Music Awards.
"10 years ago, the hashtag was created by a Twitter user and has since evolved from a way to categorise Tweets, to a fun way to add commentary to a Tweet and to a powerful tool in creating global conversations and connecting people to form movements," said Sinead McSweeney, Vice-President of Public Policy and Communication for Twitter EMEA, and Managing Director of Twitter Ireland.
"Hashtags have helped to shape some of the most important moments, conversations, and movements across the world over the past ten years."
In marking the anniversary, Twitter has released data which says the most tweeted TV show hashtag is #TheWalkingDead, while the most popular movie hashtag is #StarWars.
The most Tweeted global sporting event hashtag is #Euro2016.
The hashtag linked to Manchester United - #MUFC - was also named as the most tweeted team hashtag of the last decade.
The social media platform is marking the anniversary suitably with a special hashtag of its own, #Hashtag10.