Number Sign/Hashtag

The # symbol is commonly called the pound sign, number sign and more recently the hashtag. It is called the pound sign because the symbol comes from the abbreviation for weight, lb, or “libra pondo” literally “pound by weight” in Latin.

What is a number sign/hashtag - "#"?

The number sign, or #, is a symbol which is representative of the word “number” in the United States and Canada. It is usually used just before an actual numeral or number, and is sometimes known as the pound sign. In recent years, the symbol has also come to represent the word “hashtag” which is a label or metadata tag used to filter social networking and microblogging sites for specific content, such as on Facebook, Twitter, or on a Wordpress blog. In this instance, the hashtag appears before a word or phrase without spaces either inside the main text of a message or blog, or at the very end. Sometimes more than one hashtag is used. The effect is to define or contextualize the content of the message.

Rules of use

The number sign is used in this manner in writing: for “number one” a person may write “#1.”  The symbol shortens the words and makes them easier to convey and understand, even by people who cannot read “number one.” It is important that the # sign is not confused with other similar symbols, especially in an international context. For instance, the sharp sign in music looks similar, as does the viewdata square and a certain Chinese character meaning a well, or neat and orderly.

Using a hashtag on a social media service such as Instagram can allows users to search the photo-sharing site for a specific type of image, or images with a specific object in them. For example, “#greencantaloupe” would search the photos and locate any with green cantaloupes in them. Marking messages with hashtags allows people to collect data about public opinion, events, and concepts at various levels of society. If a search is performed on “#2016Olympics,” for instance, hundreds of tweets might be returned immediately.

Other uses of "#" - The number sign/hashtag

In the United States, the number sign on a phone keyboard is called the “pound sign,” but outside of North America, it is called the “hash key” and “pound sign” refers to the British symbol for its currency, the English pound. Hashtags have often been used for social activism, to show support for a particular cause, or help spread awareness through messaging on social media services. It's not often used as a form of punctuation. The word “hashtag” has become so prevalent in popular conversation, both actual and via social media, that the Oxford English Dictionary added it in 2014.

Hashtags began being used in information technology (IT) in order to highlight the meaning of a word or phrase. Brian Kernighan and Dennis Ritchie used it in C programming language in order to denote special keywords that must be processed first. Following this first use in 1976, the number sign was used in IRC, and Chris Messina proposed that it could be used to tag certain topics for searching and microblogging networks. The first hashtag ever posted on Twitter by Chris was “how do you feel about using # (pound) for groups. As in #barcamp [msg]?” in August 2007. During the Iranian election protests of 2009 and 2010, hashtagging became a writing style for English and Persian language users on Twitter to protest the issues. "Hashtag" was first used in a blog post by Stowe Boyd in August of 2007, and in July or 2009, Twitter began hyperlinking all hashtags in tweets to search results for specific terms for the site. In order to prevent unnatural trending or bias in hashtagging, Twitter has devised an algorithm to prevent these spam attempts. Hashtags can also be used informally or to poke fun at serious hashtags and express humor, sadness, excitement, or other contextual clues.