A hashtag, introduced by the number sign, or hash symbol, #, is a type of metadata tag used on social networks such as Twitter and Instagram and other microblogging services. It lets users apply dynamic, user-generated tagging that helps other users easily find messages with a specific theme or content. Users create and use hashtags by placing a hash symbol in front of a word or unspaced phrase in a message. The hashtag may contain letters, digits, and underscores. Searching for that hashtag yields each message that someone has tagged with it. A hashtag archive is consequently collected into a single stream under the same hashtag. For example, on the photo-sharing service Instagram, the hashtag #bluesky allows users to find all the posts that have been tagged using that hashtag.
The use of hashtags was first proposed by Chris Messina in a 2007 tweet, that, although initially decried by Twitter as a "thing for nerds," eventually led to their use rapidly becoming widespread throughout the platform. Messina, who made no attempt to patent the use because he felt "they were born of the internet, and owned by no one", has subsequently been credited as the godfather of the hashtag. By the end of the decade hashtags could be seen in most emerging as well as established social media platforms including Instagram, Facebook, Reddit, and YouTube — so much so that Instagram had to officially place a "30 hashtags" limit on its posts to prevent people from abusing their use, a limit that Instagrammers eventually circumvented by posting hashtags in the comments section of their posts. As of 2018 more than 85% of the top 50 websites by traffic on the Internet use hashtags and their use is common by millennials, Gen Z, politicians, influencers, and celebrities worldwide. Because of its widespread use, hashtag was added to the Oxford English Dictionary in June 2014. The term hashtag is sometimes erroneously used to refer to the hash symbol itself when used in the context of a hashtag. Formal taxonomies can be developed from the folk taxonomy rendered machine-readable by the markup that hashtags provide. This process is called folksonomy.
Origin and usesEdit
The number sign or hash symbol "#" is often used in information technology to highlight a special meaning. (The symbol is also called an "octothorpe" or "pound sign" in the US, and "hash" in the UK) In 1970, for example, the number sign was used to denote immediate address mode in the assembly language of the PDP-11 when placed next to a symbol or a number. In 1978, Brian Kernighan and Dennis Ritchie used # in the C programming language to indicate special keywords that the C preprocessor had to process first. In the 1986 SGML standard, ISO 8879:1986 (q.v.), # is a reserved name indicator (rni) that precedes keyword syntactic literals, --e.g., the primitive content token #PCDATA, used for parsed character data.
The International Telecommunication Union (ITU) approved in November 1988 recommendation E.161 that put the pound sign on the right side of the 0 in the 4 x 3 button arrangement for push buttons on telephones. This same arrangement is still used today in most software phones (see Android dialer for example). The ITU recommendation had 2 design options for the pound sign: a European version where the hash sign was built with a 90-degree angle and a North-American version with an 80-degree angle. The North-American version seems to have prevailed as most pound signs in Europe now follow the 80-degree inclination.
The pound sign was adopted for use within IRC (Internet Relay Chat) networks circa 1988 to label groups and topics. Channels or topics that are available across an entire IRC network are prefixed with a hash symbol # (as opposed to those local to a server, which use an ampersand '&').
How do you feel about using # (pound) for groups. As in #barcamp [msg]?— Chris Messina, ("factoryjoe"), August 23, 2007
Messina's suggestion to use the hashtag was not adopted by Twitter, but the practice took off after hashtags were widely used in tweets relating to the 2007 San Diego forest fires in Southern California.
According to Messina, he suggested use of the hashtag to make it easy for "lay" users to search for content and find specific relevant updates; they were for people who do not have the technological knowledge to navigate the site. Therefore, the hashtag "was created organically by Twitter users as a way to categorize messages."  Today they are for anyone, either with or without technical knowledge, to easily impose enough annotation to be useful without needing a more formal system or adhering to many technical details.
Internationally, the hashtag became a practice of writing style for Twitter posts during the 2009–2010 Iranian election protests; Twitter users inside and outside Iran used both English- and Persian-language hashtags in communications during the events.
The first published use of the term "hash tag" was in a blog post by Stowe Boyd, "Hash Tags = Twitter Groupings," on August 26, 2007, according to lexicographer Ben Zimmer, chair of the American Dialect Society's New Words Committee.
Beginning July 2, 2009, Twitter began to hyperlink all hashtags in tweets to Twitter search results for the hashtagged word (and for the standard spelling of commonly misspelled words). In 2010, Twitter introduced "Trending Topics" on the Twitter front page, displaying hashtags that are rapidly becoming popular. Twitter has an algorithm to tackle attempts to spam the trending list and ensure that hashtags trend naturally.
Although the hashtag started out most popularly on Twitter as the main social media platform for this use, the use has extended to other social media sites including Instagram, Facebook, Flickr, Tumblr, and Google+.
The feature has been added to other, non-short-message-oriented services, such as the user comment systems on YouTube and Gawker Media. In the case of the latter, hashtags for blog comments and directly submitted comments were used to maintain a more constant rate of user activity even when paid employees were not logged into the website. Real-time search aggregators such as the former Google Real-Time Search also support hashtags in syndicated posts, meaning that hashtags inserted into Twitter posts can be hyperlinked to incoming posts falling under that same hashtag; this has further enabled a view of the "river" of Twitter posts.
The use of hashtags has extended to television—a concept that began rising in prominence in the early 2010s. Broadcasters may display a hashtag as an on-screen bug, encouraging viewers to participate in a backchannel of discussion via social media prior to, during, or after the program. Television commercials have sometimes contained hashtags for similar purposes. Hashtag bugs appear on either corner of the screen, or they may appear at the end of an advertisement.
While personalities associated with broadcasts, such as hosts and correspondents, also promote their corporate or personal Twitter usernames to receive mentions and replies to posts, usage of related or "branded" hashtags alongside Twitter usernames (e.g., #edshow as well as @edshow) is increasingly encouraged as a microblogging style to "trend" the hashtag (and, hence, the discussion topic) in Twitter and other search engines. Broadcasters also make use of such a style to index select posts for a live broadcast. Chloe Sladden, Twitter's director of media partnerships, identified two types of television-formatted usage of hashtags: hashtags that identify a series being broadcast (e.g., #SunnyFX) and instantaneous, "temporary" hashtags issued by television personalities to gauge topical responses from viewers during broadcasts. Some have speculated that hashtags might take the place of (or co-exist with) the Nielsen television ratings system.
An example of trending "temporary" hashtags garnering viewers during broadcasts is observed on The Tonight Show with Jimmy Fallon, a variety talk show on NBC. Every Wednesday, Fallon hosts a segment on his show called "Tonight Show Hashtags," which engages viewers by inviting them via Twitter to post humorous stories based on a specific hashtag topic, such as #WhydidIsaythat, #Worstfirstdate, to #Onetimeinclass, reflecting on funny experiences in daily life. By using hashtags, Fallon creates a sense of community and solidarity among his viewers and draws a wider range of viewers through an online platform while they watch a classic, non-interactive television program. Because of its popularity, the "Tonight Show Hashtags" are usually the 'most tweeted hashtag' on Twitter, which promotes the show. By engaging viewers with a lighthearted subject and simple hashtags, Fallon can gauge topical responses from viewers during broadcasts and also use the hashtags to brand his show.
The increased usage of hashtags as brand promotion devices has been compared to the promotion of branded "keywords" by AOL in the late 1990s and early 2000s, as such keywords were also promoted at the end of television commercials and series episodes.
The late-night television comedy game show @midnight with Chris Hardwick on Comedy Central features a daily game entitled "Hashtag Wars," in which three comedians compete against one another to come up with phrases based on a given hashtag theme.
Some hashtags have become famous worldwide. For instance the slogan "Je suis Charlie," which was first used on Twitter as the hashtag #jesuischarlie and #iamcharlie to indicate solidarity with Charlie Hebdo offices attacked in Paris, spread to the internet at large.
Since February 2013 Twitter and American Express have collaborated to enable users to pay for discounted goods online by tweeting a special hashtag. American Express members can sync their card with Twitter and pay for offers by tweeting; American Express tweets a response to the member that confirms the purchase.
Organized real-world events have used hashtags and ad hoc lists for discussion and promotion among participants. Hashtags are used as beacons by event participants to find each other, both on Twitter and, in many cases, during actual physical events.
Companies and advocacy organizations have taken advantage of hashtag-based discussions for promotion of their products, services or campaigns.
Political protests and campaigns in the early 2010s, such as #OccupyWallStreet and #LibyaFeb17, have been organized around hashtags or have made extensive usage of hashtags for the promotion of discussion. Hashtags have also been used to promote official events; the Finnish Ministry of Foreign Affairs officially titled the 2018 Russia–United States summit as the "#HELSINKI2018 Meeting".
Hashtags are often used by consumers on social media platforms to complain about the customer service experience with large companies. The term "bashtag" has been created to describe situations in which a user refers to a corporate social media hashtag to criticise the company or to tell others about poor customer service. For example, in January 2012, McDonald's created the #McDStories hashtag so that customers could share positive experiences about the restaurant chain. But, the marketing effort was cancelled after two hours when McDonald's received numerous complaint tweets rather than the positive stories they were anticipating.
The use of hashtags also reveals what feelings or sentiment an author attaches to a statement. This can range from the obvious, where a hashtag directly describes the state of mind, to the less obvious. For example, words in hashtags are the strongest predictor of whether or not a statement is sarcastic—a difficult AI problem.
The YouTuber Spencer FC used the hashtag for the name and crest of his YouTube-based association football team, Hashtag United F.C..
The hashtag is also used in reference to the name of performance action-sports brand, Hashtag Board Co.
Since the 2012–13 season, the National Basketball Association (NBA) has allowed fans to vote players in as All-Star Game starters on Twitter and Facebook using #NBAVOTE. The tweets and Facebook posts must include #NBAVOTE along with the player's first and last name or Twitter handle.
A hashtag must begin with a hash character followed by other characters, and is terminated by a space or end of message. It is always safe to precede the "#" with a space, and to include letters without diacritics, digits, and underscores. In many cases, other characters are also allowed, in particular, accented characters used in many languages, but handling may vary from one client to another and from time to time as standards evolve. A discussion of hashtag standards suggests that if #Romeo&Juliet is used, different Twitter clients might link to #Romeo, #Romeo&, or #Romeo&Juliet. Hashtags are not case sensitive: a search for "#hashtag" finds "#HashTag". The use of embedded capitals (CamelCase) increases legibility and avoids confusion. A (real) pen shop should use #PenIsland rather than all lower-case. On microblogging and social networking sites hashtags can be inserted anywhere within a text, often at the beginning or the end, but also within the text, usually as a word (e.g., "It is #sunny today").
Languages that do not use word dividers handle hashtags differently. In China, microblogs Sina Weibo and Tencent Weibo use a double-hashtag-delimited #HashName# format, since the lack of spacing between Chinese characters necessitates a closing tag. Twitter uses a different syntax for Chinese characters and orthographies with similar spacing conventions: the hashtag contains unspaced characters, separated from preceding and following text by spaces (e.g., '我 #爱 你' instead of '我#爱你') or by zero-width non-joiner characters before and after the hashtagged element, to retain a linguistically natural appearance (displaying as unspaced '我#爱你', but with invisible non-joiners delimiting the hashtag).
It is considered acceptable to tag a post once when contributing to a specific conversation. Two hashtags are considered acceptable when adding a location to the conversation. Three hashtags are seen by some as the "absolute maximum", and any contribution exceeding this risks "raising the ire of the community."
As well as frustrating other users, the misuse of hashtags can lead to account suspensions. Twitter warns that adding hashtags to unrelated tweets, or repeated use of the same hashtag without adding to a conversation can filter an account from search results, or suspend the account.
Hashtags are mostly used in unmoderated, ad hoc discussion forums; any combination of characters led by a hash symbol is a hashtag, and any hashtag, if promoted by enough individuals, can "trend" and attract more individual users to discussion. On Twitter, when a hashtag becomes extremely popular, it appears in the "Trending Topics" area of a user's homepage. The trending topics can be organized by geographic area or by all of Twitter. Hashtags are neither registered nor controlled by any one user or group of users. They cannot be "retired" from public usage, meaning that any given hashtag can theoretically be used in perpetuity. They do not contain any set definitions, meaning that a single hashtag can be used for any number of purposes, as chosen by the creators of them.
Hashtags intended for discussion of a particular event tend to use an obscure wording to avoid being caught up with generic conversations on similar subjects, such as a cake festival using #cakefestival rather than simply #cake. However, this can also make it difficult for topics to become "trending topics" because people often use different spelling or words to refer to the same topic. For topics to trend, there must be a consensus, whether silent or stated, that the hashtag refers to that specific topic.
Hashtags also function as beacons that help users find and "follow" (subscribe) or "list" (organize into public contact lists) other users of similar interest.
Television broadcasters such as Channel 4 have employed the hashtag during the transmission of programmes such as First Dates and The Undateables. Research has shown that audience numbers go up when individuals can be interactive by tweeting while viewing a programme.
Hashtags can be used on the social network Instagram, by posting a picture and hashtagging it with its subject. As an example, a photo of oneself and a friend posted to the social network can be hashtagged #bffl or #friends. Instagram has banned certain hashtags, some because they are too generic, such as #photography #iPhone #iphoneography, and therefore do not fulfill a purpose. They have also blocked hashtags that can be linked to illegal activities, such as drug use. The ban against certain hashtags has a consequential role in the way that particular subaltern communities are built and maintained on Instagram. Despite Instagram's content policies, users are finding creative ways of maintaining their practices and ultimately circumventing censorship.
Famous YouTube bloggers often use hashtags to promote their videos to a wide audience. Thus, by leaving various hashtags under the video, they are trying to increase their views and gain as many likes as possible. Usually, hashtags are left under the video itself in a special line. By clicking on the hashtag you go directly to the link to the video, which are similar in topic.
Hashtags are also used informally to express context around a given message, with no intent to categorize the message for later searching, sharing, or other reasons. One of the functions of the hashtag is to serve as a reflexive meta-commentary, which contributes to the idea of how written communication in new media can be paralleled to how pragmatic methodology is applied to speech. In addition, the culture of hashtag has developed due to recent Black Lives Matter movement. In this case hashtags has been used to access vital information and news update on the topic.  Similarly, hashtags were used for the #MeToo social movement. It was used to spread awareness and empower people to fight for gender equality. The spreadability function of the hashtag was very impactful for the cause because it allowed for people's messages to reach a wider audience. Through the spread of external information regarding the #MeToo movement empowered by the use of hashtags, has caused for an increase in financial investment towards sexual assault reform.
This can help express contextual cues or offer more depth to the information or message that appears with the hashtag. "My arms are getting darker by the minute. #toomuchfaketan". Another function of the hashtag can be used to express personal feelings and emotions. For example, with "It's Monday!! #excited #sarcasm" in which the adjectives are directly indicating the emotions of the speaker. It can also be used as a disclaimer of the information that the hashtag accompanies, as in, "BREAKING NEWS: US GDP growth is back! #kidding". In this case, the hashtag provides an essential piece of information in which the meaning of the utterance is changed entirely by the disclaimer hashtag. This may also be conveyed with #sarcasm, as in the previous example. Self-mockery is another informal function of the hashtag used by writers, as in this tweet: "Feeling great about myself till I met an old friend who now races at the Master's level. Yup, there's today's #lessoninhumility," where the informality of the hashtag provides commentary on the tweet itself.
In popular cultureEdit
During the April 2011 Canadian party leader debate, Jack Layton, then-leader of the New Democratic Party, referred to Conservative Prime Minister Stephen Harper's crime policies as "a hashtag fail" (presumably #fail).
The term "hashtag rap", coined by Kanye West, was developed in the 2010s to describe a style of rapping that, according to Rizoh of the Houston Press, uses "three main ingredients: a metaphor, a pause, and a one-word punch line, often placed at the end of a rhyme". Rappers Nicki Minaj, Big Sean, Drake, and Lil Wayne are credited with the popularization of hashtag rap, while the style has been criticized by Ludacris, The Lonely Island, and various music writers.
Hashtags have been used verbally to make a humorous point in informal conversations, such as "I'm hashtag confused!" In August 2012, British journalist Tom Meltzer wrote in The Guardian that a new hand gesture mimicked the hashtag, sometimes called the "finger hashtag", in which both hands form a peace sign, and then the fingers are crossed to form the symbol of a hashtag. The emerging gesture was reported in Wired by Nimrod Kamer, and during 2013, it was seen on TV as used by Jimmy Fallon, and on The Colbert Report, among other programs. Writing in 2015, Paola Maria Caleff considered this usage a fad, but noted that people talking the way that they write was a consequence of computer-mediated communication.
- Hashflags: In 2010, Twitter introduced "hashflags" during the 2010 World Cup in South Africa. They reintroduced the feature on June 10, 2014, in time for the 2014 World Cup in Brazil, and then again on April 10, 2015, with UK political party logos for the 2015 UK General Election. When a user tweets a hashtag consisting of the three letter country code of any of the 32 countries represented in the tournament, Twitter automatically embeds a flag emoticon for that country. A similar system was implemented for the 2015 Eurovision Song Contest in Vienna, Austria.
- Cashtags: In 2009, StockTwits used ticker symbols preceded by the dollar sign to create "cashtags". In July 2012, Twitter adapted the hashtag style to make company ticker symbols preceded by the dollar sign clickable (as in $AAPL), a method that Twitter dubbed the "cashtag". This is intended to allow users to search posts discussing companies and their stocks. This is also used for discussion of currency pairings on Twitter, e.g., using #USDGBP or $USDGBP, when mentioning the US Dollar's level expressed in Pounds Sterling.
- "What Characters Can A Hashtag Include?". hashtags.org. Retrieved September 21, 2017.
- Chang, Hsia-Ching; Iyer, Hemalata (2012). "Trends in Twitter - Hashtag Applications: Design Features for Value-Added Dimensions to Future Library Catalogues". Library Trends. 61 (1): 248–258. doi:10.1353/lib.2012.0024. ISSN 1559-0682. S2CID 34506239.
- "Chris Messina on Twitter". Twitter. Retrieved November 10, 2018.
- Panko, Ben. "A Decade Ago, the Hashtag Reshaped the Internet". Smithsonian. Retrieved November 10, 2018.
- "Chris Messina's answer to Why didn't the creator of the hashtag patent the concept? - Quora". www.quora.com. Retrieved November 10, 2018.
- Parker, Ashley (June 10, 2011). "Twitter's Secret Handshake". The New York Times. Retrieved July 26, 2011.
- "BBC News – Hashtag inventor: It was an 'accidental trip over a simple idea'". BBC. December 5, 2014. Retrieved December 5, 2014.
- "The Inventor of the Twitter Hashtag Explains Why He Didn't Patent It". Business Insider. Retrieved March 19, 2016.
- "How do I use hashtags? | Instagram Help Center". help.instagram.com. Retrieved November 10, 2018.
- "Instagram Max Hashtags: How to post up to 60". itchban. Retrieved November 10, 2018.
- "Website Ranking: Top Websites Rank In The World - SimilarWeb". www.similarweb.com. Retrieved November 10, 2018.
- "'Hashtag' added to the OED – but # isn't a hash, pound, nor number sign". The Register. June 13, 2014.
- "New words notes June 2014". Oxford English Dictionary. June 2014. Archived from the original on October 7, 2014.
- "Oxford English Dictionary – Hash". Oxford English Dictionary. June 2014.
- "PDP-11 assembly language". Programmer209.wordpress.com. August 3, 2011. Retrieved August 25, 2014.
- B.W. Kernighan; D. Ritchie (1978). The C Programming Language. Prentice Hall. pp. 86 and 207. ISBN 978-0-13-110163-0.
- "Recommendation E.161 - Arrangement of figures, letters and symbols on telephones and other devices that can be used for gaining access to a telephone network". ITU. November 25, 1988.
- "Channel Scope". Section 2.2. RFC 2811
- Oikarinen, Jarkko; Reed, Darren (1993). "Channels". Internet Relay Chat Protocol. IETF. sec. 1.3. doi:10.17487/RFC1459. RFC 1459. Retrieved June 3, 2014.
- "#OriginStory". Carnegie Mellon University. August 29, 2014.
- Parker, Ashley (June 10, 2011). "Twitter's Secret Handshake". The New York Times. Retrieved July 26, 2011.
- Chris Messina ("factoryjoe") (August 23, 2007). "Twitter post".
- What is hashtag?", Mashable, 8 October 2013
- "Twitter hashtags for emergency coordination and disaster relief". Factory Joe. October 23, 2007. Retrieved September 16, 2017.
- Scott, Kate (May 1, 2015). "The pragmatics of hashtags: Inference and conversational style on Twitter" (PDF). Journal of Pragmatics. 81: 8–20. doi:10.1016/j.pragma.2015.03.015.
- "The story of the hashtag began with Iranians". Deutsche Welle Persian. 2009. Retrieved March 12, 2015.
- "Stowe Boyd, Hash Tags = Twitter Groupings". Stoweboyd.com. Retrieved September 19, 2013.
- "Twitter Makes Hashtags More #Useful". Retrieved December 27, 2015.
- "The Secret of Twitter's Trending Hashtags With Insight and Tips". AllISayIs.com. Archived from the original on May 5, 2015. Retrieved December 3, 2014.
- Mashable, By Christina Warren. "Facebook finally gets #hashtags - CNN.com". CNN. Retrieved May 16, 2016.
- Gabriel Snyder (October 15, 2009). "Anarchy in the Machine: Welcome to Gawker's Open Forums". Gawker.
- Zachary M. Seward (October 15, 2009). "Got a #tip? Gawker Media opens tag pages to masses, expecting "chaos"". Nieman Journalism Lab.
- Michael Schneider (April 21, 2011). "New to Your TV Screen: Twitter Hashtags". TV Guide.
- Todd Wasserman (December 3, 2012). "McDonald's Releases First TV Ad With Twitter Hashtag". Mashable.
- Gregory Ferenstein (April 15, 2011). "Twitter TV Hashtag Tips From Twitter's Own Expert". Fast Company.
- "Twitter Chatter Correlates With TV Ratings, But Is That Good Or Bad News For Nielsen?". International Business Times. March 22, 2013. Retrieved September 19, 2013.
- Ryan Lawler (June 10, 2012). "Twitter's Hashtag Pages Could Be The New AOL Keywords — But Better". Techcrunch.
- Heather, Kelly (February 12, 2013). "Twitter and Amex let you pay with a hashtag". CNN. Retrieved November 25, 2013.
- "Sync with Twitter". Amex Sync. Archived from the original on November 25, 2013. Retrieved November 25, 2013.
- "#HELSINKI2018 - Ministry for Foreign Affairs". um.fi. Retrieved July 11, 2018.
- Akwagyiram, Alexis (May 17, 2012). "Are Twitter and Facebook changing the way we complain?". BBC News. Retrieved June 12, 2012.
- Maynard (2014). "Who cares about sarcastic tweets? Investigating the impact of sarcasm on sentiment analysis". Proceedings of the Conference on Language Resources and Evaluation.
- "Power yourself with viral marketing - become a HashTag Genius". huffingtonpost.com. Retrieved September 16, 2017.
- "Please Log In". hashtagboardco.com. Retrieved February 20, 2019.
- "NBA and Sprint tip off NBA All-Star Balloting 2014". November 15, 2013.
- Terence Eden (February 25, 2010). "Hashtag Standards". Terence Eden's Blog. Retrieved September 21, 2017.
- "Pen Island Pens - Home". Penisland.net. Retrieved September 21, 2017.
- Martin, Rick (July 13, 2011). "Twitter Rolls Out Hashtag Support for Japanese, Korean, Chinese, and Russian". Tech in Asia. Retrieved March 5, 2015.
- International services team (April 5, 2012). "Right-to-left languages on Twitter". Twitter. Archived from the original on April 2, 2015. Retrieved March 5, 2015.
- "What is a (#) Hashtag?". Hashtags.org. June 24, 2012. Retrieved February 22, 2014.
- "The Twitter Rules". Twitter, Inc. Retrieved September 22, 2017.
if you post multiple unrelated updates to a topic using # ...
- The Tonight Show Starring Jimmy Fallon (September 24, 2013). ""#Hashtag" with Jimmy Fallon & Justin Timberlake (Late Night with Jimmy Fallon)". YouTube. Retrieved August 25, 2014.
- "Instagram banned hashtags". BBC.co.uk. November 7, 2013. Retrieved November 25, 2013.
- Olszanowski, M. (2014). "Feminist Self-Imaging and Instagram: Tactics of Circumventing Sensorship". Visual Communication Quarterly, 21(1), 83–95. Retrieved February 8, 2015, from http://www.tandfonline.com/doi/abs/10.1080/15551393.2014.928154#.VNgGT7DF-7FF-7F
- Wikström, Peter (2014). "#srynotfunny: Communicative Functions of Hashtags on Twitter" (PDF). SKY Journal of Linguistics. Retrieved May 15, 2016.
- Welle (www.dw.com), Deutsche. "#MeToo and more — five hashtags for equality | DW | 15.10.2019". DW.COM. Retrieved September 3, 2020.
- Brown, Dalvin. "19 million tweets later: A look at #MeToo a year after the hashtag went viral". USA TODAY. Retrieved September 3, 2020.
- Caleffi, Paola-Maria. "The 'hashtag': A new word or a new rule?" (PDF). Skase Journal of Theoretical Linguistics.
- Anna Mehler Paperny (April 13, 2011). "Jack Layton's debatable 'hashtag' #fail". The Globe and Mail.
- "Canadians atwitter throughout debate". CBC News. April 13, 2011.
- Zach Baron (November 3, 2010). "The Ten Best Quotes From Kanye West's Epic Hot 97 Interview With Funkmaster Flex". The Village Voice. Archived from the original on July 22, 2013. Retrieved July 22, 2013.
- Rizoh (July 7, 2011). "A Brief History Of Hashtag Rap". Houston Press.
- David Mendez (May 22, 2013). "The Lonely Island Puts Hashtag Rap In Its Place (Looking at You, Drake)". Tucson Weekly.
- Jeremiah Tucker (December 17, 2010). "Jeremiah Tucker: Hashtag rap is 2010's lamest trend". Joplin Globe.
- Goel, Vindu; Bilton, Nick; Gelles, David (September 12, 2013). "A Short Post, a Big Splash: #TwitterIPO". The New York Times. Retrieved January 19, 2019.
- Bilton, Nick [@nickbilton] (September 14, 2013). "My first byline on A1 of the ..." (Tweet). Retrieved September 14, 2013 – via Twitter.[dead link]
- "Birds Eye launches Mashtags – social media potato shapes". The Grocer.
- "hashtag (noun) definition and synonyms". Macmillan Dictionary. Retrieved September 16, 2017.
- Tom Meltzer (August 1, 2012). "How to say 'hashtag' with your fingers". The Guardian. Retrieved March 20, 2014.
- Nimrod Kamer (March 2013). "Finger-Hashtags". Wired. Retrieved March 20, 2014.
- Nimrod Kamer (February 26, 2014). "I invented finger hashtags—and I regret nothing". The Daily Dot. Retrieved March 20, 2014.
- @IBIS_journal (May 29, 2019). "Our new medal has been designed by our own @stevedudley_ who has a background in design. It [...] uses icons of birds and other #ornithology-related items including people and tech" (Tweet) – via Twitter. [see attached image for explanation of the hash character]
- "Twitter Supports World Cup Fever with Hashflags". Ryanseacrest.com. June 11, 2010. Archived from the original on November 29, 2010. Retrieved August 5, 2015.
- "What are Hashflags?". Howto.digidefen.se. June 10, 2014. Retrieved August 25, 2014.
- Ben Woods (June 10, 2014). "Twitter brings back hashflags just in time for World Cup 2014 kick-off". Thenextweb.com. Retrieved August 25, 2014.
- "Twitter just launched election hashflags". BBC News. Retrieved April 15, 2015.
- "Eurovision Twitter hashflags go live!". eurovision.tv. Retrieved February 22, 2017.
- Wong, Matthew (August 17, 2012). "VCs and Start-Ups Pin Their Hopes on Pinterest". The Wall Street Journal. Retrieved May 28, 2013.
- Taylor, Colleen (July 1, 2012). "Howard Lindzon on Why He Sold His Twitter Stock, And The 'Hijack' Of StockTwits' Cashtags [TCTV]". TechCrunch. Retrieved May 9, 2013.
- Kim, Erin (July 31, 2012). "Twitter unveils 'cashtags' to track stock symbols – Jul. 31, 2012". Money.cnn.com. Retrieved November 12, 2013.
- "Twitter makes stock symbol $ 'cashtag' links official, following # and @". The Verge. July 30, 2012. Retrieved November 12, 2013.
- babtunde, Saka. "Is Hashtag the New Way of Tweet- (Case Study) - NAIJA NEWS TODAY & LATEST BREAKING NEWS". www.newsliveng.com. Retrieved April 24, 2019.
|Wikimedia Commons has media related to Hashtags.|
- Wikipedia internal hashtag search engine – for hashtags used in edit summaries
- Veszelszki, Ágnes 2016: #time, #truth, #tradition. An Image-text Relationship on Instagram: photo and hashtag. In: Benedek, András; Veszelszki, Ágnes (eds.): In the Beginning was the Image: The Omnipresence of Pictures: Time, Truth, Tradition. Frankfurt am Main: Peter Lang GmbH, Internationaler Verlag der Wissenschaften, pp. 139–150.