7 things you should know about Twitter hashtags

7 things you should know about Twitter hashtags

Including the story behind all of those #stlwx tweets.

Storified by Erica Smith · Wed, Jul 11 2012 08:59:30

#FreesePlease helped send Cardinals third baseman David Freese (@dfreese23) to the All-Star Game in Kansas City.
Let’s join forces Cards Nation: RETWEET THIS to cast a vote for David Freese! #FreesePlease #FinalVote http://atmlb.com/NaUYuy!St. Louis Cardinals
#STLwx kept several informed of weather conditions during the recent heat wave and severe storms.
106° at 1pm in #StLouis. #stlwx #heatwaveJohn Dissauer
A nice ongoing downpour in Lindenwood Park. Finally! #stlwxBrent Jones
Clouds last night. #stlwx http://instagr.am/p/M3OeMkuF-n/Chris Franklin
And any time the Cardinals are playing, you can almost catch a play-by-play by following #STLcards. (You’ll also see many uses of #Cardinals, #Cards and #CardinalsNation — the official @Cardinals account has used all of the above.) 
Hashtags are one of the overlooked keys to Twitter. For those unfamiliar with them, a hashtag is a phrase or string of letters and/or numbers that follow a hash, known by many as the pound sign. Twitter and Twitter clients link — clicking on a hashtag will produce a list of tweets that include the same hashtag.

Hashtags can be used anywhere in a tweet — beginning, middle or end. They must include the hash symbol to be clickable: #Friday is a hashtag; Friday is not. Tweets can include multiple hashtags, although Twitter’s best-practices recommends not using more than two per tweet. 

Anything can be a hashtag, and they tend to fall into two categories: Topics and humor. 

#STLwx is used for weather-related tweets. (WX is old-fashioned shorthand for weather. The abbreviation was first used on the telegraph, the original short-burst communication system.) #STLblues tags tweets about the hockey team. #WinningOnMonday could indicate a good Monday (and hasn’t been used very often lately); #sigh may add a bit of exasperation; and #MOsen clarifies that the tweet is about the Missouri Senate. 

Anyone can create and use a hashtag. Capitalization is not important, although capital letters often are used to make phrases easier to read. Hashtags cannot include spaces or punctuation (#ImHappy works; #I’mHappy doesn’t), and cannot start with a number.

Hashtags also can be used to route information. Users that include #fb, for example, likely use the Selective Tweets app to publish the tweet to Facebook. (LinkedIn recently eliminated a similar feature.)

When disaster strikes or news breaks, hashtags often follow and become a type of shorthand. #STLwx and #STLtornado were widely used in tweets about the April 2011 tornado, as well as #lambert and names of affected towns.
Air National Guard building damaged at Lambert, in addition to damage at the main terminal and Terminal C. #stlwxWeatherbird
police: nursing home on Doddridge being evacuated as a precaution bc of gas leak/power outage concerns #marylandheights #STLtornadoPatrick M. O’Connell
If you smell gas, call Laclede Gas 24hr hotline @ 314-342-0800 #STLtornadoStLouisCo
Similarly, #JoplinTornado appeared on Twitter as soon as it was clear a tornado had hit the southwest Missouri town — even before it was apparent how much damage the storm had caused.

During uprisings in Egypt, Bahrain and Libya, protests and reports of violence often were hashtagged by city and country. The Occupy Wall Street movement saw similar hashtag uses by city. Tweets about Japan’s devastating earthquake were tagged several ways, including #Japan, #earthquake, #JapanQuake. More recently, nearly a dozen hashtags were used in tweets about the Colorado wildfires — each sharing information about a different fire.

Not every hashtag traces its roots to disaster. Remember the squirrel that sprinted across Busch Stadium last season? Within seconds of its Oct. 4 appearance, a #RallySquirrel hashtag popped up on Twitter. (There were more squirrel tweets than Fredbird tweets last season. Take a look at last season’s Cardinals’ tweets.)

Hashtags often evolve or change. In some cases, multiple hashtags may refer to the same event, like #stlwx and #stlweather. Typically the hashtag that is used the most wins out — local media and government accounts tend to use #stlwx, and other Twitter users have followed suit. 
A heat advisory and excessive heat warning remains in effect until 7 pm Monday. http://www.crh.noaa.gov/lsx #stlwx #mowx #ilwx #heatwave #stlNWS St. Louis
6:49 PM: Severe Thunderstorm Warning in effect for Central St Louis Co (I-64) through 7:30 pm CDT #stl #stlwx http://nixle.us/7ZQ2ASt Louis County OEM
10 days in a row of 100+ through Saturday. 8 daily high records. Warmest start to a year on record. Enough! Heat wave is broken #stlwxSteve Templeton KMOV
When creating a hashtag for wide use, tweet the hashtag and an explanation, so others know what it means. Sometimes a reminder is handy, too
For those wondering why #STLwx is trending: WX is short for weather. Basically, we’re all tweeting about the heat today in St. Louis.Erica Smith
As with nearly everything online, hashtags can be spammed. Anyone can use hashtags, including scammers, spammers and evil robots. Spam tweets often offer something free or include only a link and the hashtag. A general rule of thumb: If you don’t know or trust the person behind the tweet, don’t click on the link. If a user has no followers and is following no one, yet is tweeting links and hashtags, it’s likely spam. Block and report Twitter spam, which helps Twitter keeps hashtags scam-free.