Vocabulary Lesson: Hashtag (#)

A hashtag is a keyword or short phrase used in microblogging to tag, classify, and sort a message. It often helps to further define the missive. Hashtags can not have spaces or punctuation.

Hashtags are often used on Twitter and Facebook. They also appear on Instagram. Sometimes a person will say the word "hashtag" out loud, followed by an oral tag. They are dorks and should be ignored. Here are some examples from Twitter:

Thank you, Statue of Liberty, for always lighting the way to freedom, truth, and yes, even New Jersey. http://t.co/73ax1FFFRb #ThankYouNotes
— Late Night (@LateNightJimmy) December 14, 2013

Gah! Taking notes from the college plays...and throwing in to retro Steelers tricks! I love Troy. #SteelersNation
— Kayleigh Elizabeth (@kayleidoscope) December 8, 2013

You can identify it by its preceding "#" You may recognize this as the "number sign," or the pound key on your phone. In press releases "###" signifies the end.

Hashtags can appear anywhere, but are commonly used at the end of the missive. On Twitter, popular hashtags are turned into "Trending Topics." (Some of the topics are paid for by sponsors.)

If you click the hashtag—the whole phrase with the pound sign—you will see all updates with that hashtag on the network. This is what happened when I clicked "#Caps"

Before I send you into that tagged world, some tips on using hashtags yourself:

It is considered bad form to use too many hashtags in a post. Consider limiting it to no more than three, though one is probably best. Make sure your hashtag is an identifier (like in the examples above) and/or the subject of your tweet. Moreover, make sure it is specific. (Don't use #art when #sculpture would be better.) Finally, your hashtag must be relevant.

Additional Resources:
Using hashtags on Twitter, Twitter Help Center
How do I use hashtags?, Facebook