WiredPen

Like any new communications technology, Twitter has its own shorthand. Some terms piggyback off of older technologies, some re-define pre-existing words. Here’s a quick guide to TwitterSpeak and etiquette:

• @username:
  A form of conversation on Twitter. @username  either directs a Tweet to someone or indicates a reply to a Tweet that person has sent. When the @username begins the Tweet, Twitter counts this as a “reply” and when the @username appears somewhere else, it is a “mention”. Both replies and mentions can be viewed in the “replies” tab of the Twitter website (when you are logged in and on your “home” page; only you can see this tab).
• #topic:
  AKA “hashtag”, this is a way to group tweets by keyword. It is particularly useful for events and groups.
• DM or DT:
  A private (direct) tweet. Syntax: D username (note the space). Direct tweets do not appear in the public timeline.
• Favorite:
  A “bookmarked” tweet. Consider your “favorites” as a reflection of you (“brand me”). If you’re a business or a person, sprinkle some Twitter kudos in those favorites — with the operative word being sprinkle!
• Follower:
  Someone who sees your tweets in their TweetStream. Following is, generally, not a reciprocal arrangement like it is with Facebook or LinkedIn. However, an account holder can chose to make tweets viewable only to followers (protected account); in this instance, the account holder approves the followers. In addition, it is possible to block someone from following. A blocked account cannot “follow” your tweets but can easily see your public tweets in a search (or through another Twitter account).
• RT or Retweet:
  Analogous to forwarding an email; re-sending a tweet sent by someone else. Courtesy: include the @username of the person who authored the tweet. Remove multiple instances of “RT” (ie, edit!). Consider revising in your own words and then crediting the sender with via @username.
• Tweet:
  A 140-character message sent to Twitter via phone, the web, or a third-party applications. Tweet are public and can be read on the public TwitterStream with two exceptions: (1) direct tweets and (2) protected tweets.
• TweetUp:
  A real-world meeting of people who have connected via Twitter.
• TwitterStream:
  A collection of tweets; usually refers to the stream of tweets sent by everyone that you follow but may refer to the public timeline of all tweets.
• Twitterati:
  Celebrity and a-list Twits (or Tweeple or Tweeters)

I’m quite certain that this only begins to scratch the surface! What have I missed?