I have created or heavily promoted several tags and codes that are in everyday use on Twitter, so I get asked a lot. "what does this or that mean?"  I've listed the common ones below to save me some time and keystrokes in the future. If I've left out anything obvious that I use often, please let me know.  I'm not going to make this a glossary of all codes in use. Just the ones I use. There is a need for such a glossary,as the one's I've seen are either very dated, or very messy.

Signal Codes

VIA  -  I came upon this resource or person by way of the via: @name.

HT  (or h/t, or simply ^@name)  A hat tip. And acknowledgement to the person who brought the item to my attention.  Often preferred over "via" when substantial changes were made to the tweet content, meaning, or purpose, but where some credit/appreciation is still due. While HT is the most common variant, I've now switched to the programmer's "hat" (^) symbol. It saves two characters (including the space after HT), and that is not an insignificant savings in Twitterville's 140 character space.

FTW – "For The Win."

Codes Created By Me

I've also conceived or embraced a few codes that everyone would use, were I ever King.  Some of my followers and friends use them now.

MT — Modified Tweet/Transmission. The tweet was substantially changed to mock or clarify.

BL  — Broken Link/Resource.  Sender should repair and resend.

CC — Carbon Copy routing to list of people.  Do not retweet (or the recipients get tweet-bombed).

CR — Creator Role." Based on Dublin Core meta data standards. Signifies that @name mentioned before the CR code had some kind of creative authorship or moderating role in relation to the Tweet or resource.  The precise role is beyond the scope of the code, and a level of detail that cannot be conveyed in a tweet. This code at least affirms there is such a role relationship to be further discovered.

QT  — Quote contained.  Used when calling out a quote which might appear in the payload item of a link, and where this isn't room or desire to attribute the speaker. Without this, it's not clear that the tweeter is not the one speaking.  There are other uses for this that I will detail some other day.  Example:
        QT "These republicans are all a bit unhinged." http://foo.to/xyaz

SMT — See My Tweet.  Instructs someone to see a recent tweet, probably not very far down their timeline.  Especially useful when instant messaging, texting or emailing, and you don't wish to repeat what you just tweeted.

Code Glossaries

• Top 50 Twitter Acronyms, Abbreviations and Initialisms by @digiphile — A very good guide by a saavy social media thought leader.

Hashtags

#p2 — The "clear channel" umbrella tag for Progressives (you may know them as "Liberals") to connect up and share resources and information across Twitter and other social networks. Read its history and mission here: About the #p2 Tag For Progressives.

#tcot  — Top Conservatives on Twitter.  In reality, it's mostly unhinged teaparty whack jobs, but it's entertaining for some when there's nothing on TV. I usually include this tag in a tweet when I believe the content is of interest to the conservatives wrecking America, or is simply so deliciously mocking that they shouldn't be left out of the mirth.

#tlot — Top Libertarians on Twitter. People who wanted to maintain some distance from the whackjobs in #tcot (see previous), but ended up with their own homegrown variation of the tag. After all, as Drew Carey said, "A libertarian is just a conservative who still gets high."

#ocra — Organized Christian Resistance Alliance. A fringe conservative group who should be watched closely before they bite the heads off too many squirrels.

#WTL – Wingnut Threat Level.  A color-coded system for indicating the current alert status of the biggest threat to democracy since Rush Limbaugh. I created this tag because someone had to.

Hash Tags Created By Me

#ff — Alias for "#FollowFriday," but also being repurposed to mean: "Friends to follow."   It basically means, "I am recommending these [ @names in this tweet ] to my followers. Read more about it, and my redefinition of it here.

#Hatriot — Means "this tweet concerns a Foxbagger, Limbaugh/Beck listener,  or some other strain of right wingnut.  Those who know me, know I've been using this term since 1996, on various services. I neglected to add it to Urban Dictionary (only started doing that with my terms recently), and only recently did someone else finally get around to doing that. And that's fine. I just love the term. Credit is for those kids on the FreeCreditReport.com ads.

Hashtag Directories

• Hashtags.org — A dictionary of tags (which are best picked up by just watching and asking).

Words and Terms Coined by Me

My Urban Dictionary Contributions

Twictionary.com  —which I administrate, had all sorts of Twerms I've created, defined, or just use a lot.