‘@’ or ‘at’ is used to tag other people into your comment, post, or message. When you add @, Twitter will notify the person you tagged. For example, you can type @Joshua and Joshua will be notified about the message you wrote.
2. RT (Re-tweet)
This is typed at the end of a post. RT encourages other people to re-tweet your post.
3. PRT (Please Re-Tweet or Partial Re-Tweet)
PRT sends a message to readers that the tweet has already been edited to accommodate the addition of username.
4. OH (Overheard)
OH is used during conference. OH signals readers that the source of the post is overheard from other source.
5. BTW (By The Way)
BTW is used to signal a change of topic. It has the same meaning with the word ‘segue’.
6. FTW (For The Win)
For the win is a positive remark done in Twitter.
7. FTL (For The Loss)
FTL is opposite of FTW. It signifies being frustrated, disappointed, dismay, and disapproval.
8. IRL (In Real Life)
IRL obviously tells you that not all things in Twitter or in the online world are necessarily true in the real world.
9. (FTF or F2F) Face to Face
This is a desire that a Twitter user wants to meet another user in real life (IRL).
10. IMHO (In My Honest Opinion or In My Humble Opinion)
This is to tell other twitter users that the remark made is based on personal opinion and not on facts. IMHO is also a way to assert one’s self without being too offensive.
11. YMMV (Your Mileage May Vary)
Simply means that your experience with regards to a product or service may differ from other people’s experiences.
12. BR (Best Regards)
This is a courteous way to ask for something. BR is also used when there is a dispute or to nicely introduce yourself.
13. B/C (Because)
B/C is used to cite a reason. This should not be confused with BCC which means blind carbon copy and is used in email.
14. JV (Joint Venture)
JV means collaboration between one or two Twitter users.
15. LMK (Let Me Know)
Simply means you like to be informed.
16. TMB (Tweet Me Back)
This is a request for another user to reply to a post.
17. DM (Direct Message)
DM means to talk to a twitter user in private.
18. LOL (Laughing Out Loud)
LOL expresses being humored.
19. IOW (In Other Words)
IOW lets you cite other words or perspective to express a thought.
20. IMX (In My Experience)
IMX expresses one’s experience.
21. # (Hashtag)
# sign is used to mark a particular trending topic. If you put a ‘#’ next to a word, you let your post to be indexed in Twitter’s search engine. For example, you typed #government. People who will search for the word ‘government’ will be able to find your post.
It is a message that tells twitter users that the tweet is something of great interest.
23. TBH (To Be Honest)
This is a remark used to show people’s honesty and/confession.
24. MT (Modified Tweet)
It means that the tweet’s content has already been modified to about 1/3 of the original content.
25. ICYMI (In Case You Missed It)
This is commonly used by internet marketers who utilize Twitter as part of their social media advertisements. ICYMI is very useful if you want to re-post something that you want readers to be reminded of.
It is a demarcation that a post or tweet is being endorsed by other Twitter users. +1 has almost equivalent meaning with ‘like’ on Facebook.
27. H/T (Hat Tip)
H/T is another way of liking a post.
28. TL;DR (Too Long; Didn’t Read)
This is a very convenient way to summarize a somewhat long article.
This symbol is used to separate statements. Rather than writing the statement from one line to another, | is used to make the post look cleaner and streamlined.
30. SMH (Shaking my Head)
This abbreviation has different uses. It can be used to describe a wide range of emotion such as confusion, amusement, amazement, disappointment, and others. It can also be used as a stand-alone comment to a particular link or tweet.
31. BRB (Be Right Back)
It means that the user will be out for a short period of time.
32. EM or EML (Email)
EM is used to refer to an email server or the act of sending an email itself.
33. Fab (Fabulous)
FAB is an expression of amusement or amazement.
34. FYI (For your Information)
FYI is an opening or introduction leading to the presentation of information.
35. GTG (Got to Go)
GTG signifies the person needs to go immediately.
36. IDC (I Don’t Care)
IDC signifies being indifferent.
37. ORLY (Oh Really)
– See more at: http://www.twelveskip.com/tutorials/twitter/230/twitter-dictionary-top-37-twitter-abbreviations-and-acronyms#sthash.s0Kk1ya9.dpuf