A hashtag (or hash tag) is a word "tagged" with a prefix and added to a Tweet message sent via Twitter. Hashtags are used to identify what the Tweet is about and serve as simple substitutes for more traditional search engine optimization (SEO).
Hashtags help identify a keyword for search engines and for other Twitterer's looking for certain types of messages when using Twitter's search feature.
Hashtags in Tweets are recognized by many blog services, including WordPress, but may cause "pingbacks" to default to a spam folder.
Hashtags work in a similar way as tags created for blogs or Flikr, but how you create them is different.
To create a hashtag, preference the "tag" (keyword) with a pound sign (#). Hashtags are inserted into the Tweet itself usually at the end of the Tweet.
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