So, recently I decided to compile my rudimentary research (and I do mean rudimentary) into the subject of fan fiction. While I was putting it all together, I knew that I wanted to define some terms that I noticed came up frequently, but that an outsider probably wouldn't understand. I also wanted to demystify some of the acronyms that are very common, because I know that during my internet searching, I spent a lot of time staring at them and trying to puzzle out what words they stood for (I was wrong 99% of the time.) That's all this really is, a simple glossary for the terms you would encounter if you wanted to explore the world of fan fiction, or if you plan on joining any dedicated fandom.
Because these fandoms typically have members that participate in fan fiction in some fashion, it's best to understand some of the basic terms so you know what the hell people are talking about. My only caveat is that this list is far from encompassing all of the terms related to fan fiction, there really are a lot of different terms. I've covered what I think are probably the basic terms someone would need, but I avoided a good chunk of story descriptors because, for the sake of full disclosure, they had to do with sex and I didn't feel like writing line after line about words to describe other people's kinks.
These terms are some of the ones that are used: in respect to the nuts and bolts of fan fiction, they're the basic jargon that describe the bare bones of a work.
Canon: Canon describes any aspect that actually exists in the show/movie/book/etc. that the fan fiction is being based on.
Headcanon: This is used to describe a writer's personal opinion or beliefs they have about the original canon that hasn't technically been proven wrong by creator of the original work.
Fan Service: Used to describe when the person who created the original work finds away to acknowledge fan-held beliefs about the show/book/etc, into the actual story. This term can be changed to a term that is specific to a fandom such as "Jossed" for the Buffy the Vampire Slayer fandom (referring the show creator Joss Whedon) or "Kripked" for the Supernatural fandom (here referencing the show's creator, Eric Kripke)
WIP (Work In Progress): Works labeled as WIP are obviously ongoing and incomplete at that time.
Drabble: From what I can tell, a drabble is a fairly short
work, but there seems to be some debate on how long they are; it appears
to me they don't exceed 500 words.
Novel: Used to show that the work is, or will be, about 300,000 words in length. As with drabbles, the exact length is in debate.
Big Bang: This is a challenge of sorts to fan fiction writers to write long stories. The writers also team up with other fans, who are artistically inclined, who will create artwork based on the writer's work.
Podfic: Basically, when either the author of a story, or someone they gave permission to, reads a story out loud in a podcast format.
Beta: A beta proofreads a writer's work before they post it.
I noticed in my travels that works focused on character relationships are a huge part of the fan fiction world, so if you're going to be encountering people that participate, it might help to know these terms/acronyms...
Shipping (verb, sometimes used as a noun, Ship): This term refers to supporting a relationship between two characters (hence the "ship" part). Some of these relationships are previously established in the original work, aka canon compliant, or they can consist of characters that aren't together in the actual story. The actual pairing is referred to as a "ship" by some. Examples of "ships" could be: Harry/Ginny for the Harry Potter series (this would be canon compliant) or the infamous Kirk/Spock for Star Trek(which is non-canon compliant, because it is not recognized in the actual series/films).
OTP (One True Pairing): This is an acronym I saw frequently and had to look up, because it seems to be used consistently as an acronym. A OTP is used to refer to a fan's favorite relationship pairing, whether canon compliant or not.
OT3: A derivative of OTP used when a fan's preferred pairing actually involves 3 people.
Slash: Slash is used to describe relationships that consist of same sex pairings. Sometimes denoted as M/M or F/F.
Het: An abbreviation of the word heterosexual, this indicates a male/female relationship. Sometimes shown as M/F.
Gen: Used to denote a story where there aren't any blatant romantic pairings. From what I can tell it's kind of like a G rating.
The following terms are used to give the reader an idea of what type of story the writer is writing. Multiple terms can be used to describe one story.
! (Exclamation point): At first, I had no idea why most of the descriptions of stories had an ! in them. Apparently this is used to show a reader in advance what type of direction they are taking the story. For example, if in a story the writer wanted to make the character much darker than they are in canon, they would show this by putting this at the beginning: Dark!characterA.
PWP: This acronym seems to have two different phrasings that mean the same thing. It can stand for "Porn Without a Plot" or "Plot? What Plot?", either way, this indicates that the story is one of the infamous fan fiction works that focuses solely on sexual content.
Crack: Sometimes used as "Crack!fic." When the author uses this term, they are acknowledging that the story they wrote is deliberately silly or over the top. I suppose this is because the reader would probably read it and think "this person must've been on crack when they wrote this."
Alternate Universe (AU): Any story where the characters are placed in universe where a key factor has changed. This can be something small like someone who died never died or the entire concept can change, such as all the characters being in high school or college.
Crossover: Just like in comic books, a crossover is just a story where one set of characters meets another in one of their worlds.
Angst: This one is pretty obvious. It refers to a story having a lot of issues that plague the characters.
Fluff: As the word implies, this indicates the story doesn't have any angst or bad things happen. These stories are just supposed to show the characters having fun and being happy.
Hurt/Comfort: A story where one of the characters experiences some sort of trauma (physical or emotional) and another character provides comfort afterward.
UST (Unresolved Sexual Tension): Yet another acronym I tried to puzzle out, this one is pretty self-explanatory once you know what the letters stand for, basically: people want to have sex.
RST (Resolved Sexual Tension): Once again, pretty obvious once you know the words: people had sex.
Rule 63: Apparently there are "Rules of the Internet" (I didn't know that, going to have to put that on my "look into further" list) and the 63rd says that in any fictional universe, there is always a female version of a male character. This can be used along with the term "Genderswap" in regards to a work.
This is only a small portion of the terms that are used in the world of fan fiction, but these are the ones that I saw on my ramblings through the internet and the ones that had me stumped for a bit. Down my list of sources, there's a link to a website that I stumbled on that has a ton of terms and their meanings if you want to look into this further; it's the first one in the list.