Oh, yes, fandom. You are most certainly On Notice(tm).
Past "On Notice" Fandom Trends
1.) The Oh-So-Clever Mystery Lover Fanfic
What It Was: Character A is apparently in love with/having sex with/getting married to a bundle of nondescript (and very occasionally genderless) pronouns. You, the reader, get the fun of trying futilely to guess the identity of this pronoun bundle, while the author feeds you deliberately misleading "hints." A proper fanfic of this nature will trick you into thinking the Mystery Lover is three or four different people, eliminating each, until the end -- where it turns out the Mystery Lover is someone far less likely.
Why It Was On Notice: The entire point of the fanfic -- and I do mean, the entire point -- was to surprise you at the end. There is no replay value; and often the Mystery Lover revealed is someone horrifying. (Like, say, Sora/Yen Sid.) But the really awesome thing is the way these fanfics are, essentially, Mad Libs With Kissing. Even when the author is really writing a couple they like and would like to see more fanfic about, they haven't contributed anything to their chosen pairing, because the nature of the Mystery Lover Fanfic means that it is so generic that even fans of the couple (should there be any) can't really enjoy it. Fail.
2.) "Should Character A get together with Character B or Character C? Vote in your comment!"
What It Is: The deplorable, largely FF.Net-exclusive phenomenon of inflating reviews for a fanfic (and avoiding actually plotting things out yourself) by asking readers to review your fanfic and tell you what to do with it.
Why It Was On Notice: For god's sake, people. Grow a spine. If you really don't care whether Character A dates Characters B or C, here's a wild notion: write about something else.
Current "On Notice" Fandom Trends
1.) The Desperately Original Pairing (AKA, the Crack Pairing)
What It Is: Two characters who have never spoken to one another and sometimes never even met (where Never Met On Screen is the slightly less hideous cousin of Never Met Period), who the author nonetheless believes would make an awesome couple if only they ever looked each other in the eye. The DOP is usually an allergic reaction to an overcrowded fandom, where the sensible pairings have all been beaten to death. (See also: Harry Potter.)
Why It's On Notice: DOPs serves no actual purpose in a fandom, but they would not hurt anything if it weren't for the tendency they have to attract huge followings (ironic, given their purpose). These followings only wind up contributing to the fandom's oversaturation, becoming the very thing their creators hated in the first place.
2.) It's Canon to Me
What It Is: A very typical, "obvious" pairing between a male main character and a female main character where smiling at each other means they're clearly going to get married before the end of the game/TV show/movie/book series. Key features of the "It's Canon to Me" trend include the pair in question never having kissed or indeed displayed real, concerted romantic interest in one another.
Why It's On Notice: We all know this happens a lot -- it's very formulaic, very Hollywood: main guy gets main girl. But shockingly, many fandoms out there are not in fact romantic comedies. And your OTP is not canon unless it happens in canon. Until that point, just because it may be more "likely" to happen (and I've seen this rule applied to some things, like Hayner/Olette, that very nearly qualify as Crack Pairings -- or worse, to characters like Axel and Larxene, who canonically hate each other), does not make it any better than any other pairing out there. And in fact, proponents of these pairings tend to ignore weighted canonical evidence in other, less traditional directions. (See also: Harry/Hermione.)
Additionally: These fans are themselves On Notice, for the hysterical way they froth at the mouths when their supposed canon is threatened by events everyone else can see coming from miles away. No other fans have so loudly sobbed, railed against the creators, or left fandoms entirely in self-centered huffs. "It's Canon to Me" is like nationalism -- merely annoying in small doses, lethal in large ones. I'm literally afraid of what would happen if Kairi got together with Riku instead of Sora, and more than a little nervous of the reaction when CoM:RC has an opportunity to show how Axel really felt about getting Larxene killed. These people are crazy.
3.) In the Japanese Version...
What It Is: A claim made by really desperate fans that such-and-such event/character relationship/portion of canon is totally different "in the Japanese version." The truly unpleasant part of this claim is that it is usually made by people who have never seen/played the Japanese version of anything in their lives.
Why It's On Notice: There is no good rebuttal to this claim, unless you happen to be in possession of never-before-seen-but-official subtitled copies of everything relevant, and can link to it at will. The person using this argument is therefore free to make up all sorts of ridiculous, self-serving tripe, knowing that he or she will never, never get caught.
Additionally: These fans are also on notice, for spreading confusion and misinformation among the ranks. Repeat after me: it is wrong to mislead other people for my own personal benefit. It is wrong to lie about my fandom just to win an argument. It is morally reprehensible to make everyone, everywhere, doubt real canon.
All Notice Boards(tm) are the intellectual property of Steven Colbert. No copyright infringement intended. I just love that guy.