Big Screwed-Up Family: Jake's family: his dad wants him to go to the same college as him and have the same job as he, his mom is willing to sleepwith him to complete the illusion, and his sister is endlessly trying to have sex with him. At first, it seems as though they are spoofing Cruel Intentions and that they are Not Blood Siblings until she affirms "only [related] by blood".
The conjoined twins really do make up one decent chick... they wind up becoming Prom Queens.
The albino hippy at the start of the movie appears during the closing credits, this time mentioning that her retinas have burned out and she needs help... in song.
During the film The Breakfast Club, a piece of pimento loaf is tossed onto a statue. This movie's parody of that movie is filmed in the same library, and starts with said piece of pimento loaf finally falling off of the statue.
Katherine: So what if we have the same mother?/Tonight I'm gonna fuck my brother!
Butt Monkey: Poor, sweet Ricky. He tells Janey that he's in love with her to her face, only for her to completely ignore him. Ends up broken and battered trying to beat the Big Man on Campus to the Airport, as he gets hit by a couple dozen cars. Ends up starting the Slow Clap... which gets him beaten up again.
The Cameo: Molly Ringwald, Melissa Joan Hart, Sean Patrick Thomas. Joan Hart's can be seen as a parody of Sarah Michelle Gellar's cameo in She's All That.
Catch Phrase. The Token Minority lampshades this: "I'm just supposed to smile, and stay out of the conversation, and say things like 'Damn!', 'Shit!' and 'That is whack!'" Later, there is this brilliant exchange:
Token Black Guy: *clears throat*
Other Black Guy: what?
TBG: I'm supposed to be the only black guy at this party.
TBG: I know—
Both: It's whack!
Caught with Your Pants Down: Parodied: the teenage girl tries to have some "alone time" with a dildo on her eighteenth birthday, when her parents, grandparents, siblings, family pets, pastor, and the girl scout troop she mentors enter in quick succession.
Contrived Clumsiness: Parodied. The heroine who already wet from jumping the pool, and the villainous Alpha Bitch, sarcastically feigning clumsiness, spills a bottle of WATER on her. The heroine reacts with humiliated tears.
Made even sillier by someone in the background shouting "That's gonna stain!"
Crowd Song: The one before prom. Lampshaded immediately afterwards: the participants look at each other and leave awkwardly.
Expy: Aside from the Stock Characters already mentioned, Ox is a blatant expy of Oz, what with only being a single letter off on the name, and having the same attitude towards sex and love that Oz ended the first movie with.
Europeans Are Kinky: Parodied with Areola, the foreign exchange student who is constantly nude.
Lampshaded with the "Dainty Girl", in a Shout-Out to the bathroom scene in Detroit Rock City (except with an unending stream of poo). As an added bonus, an English professor is heard berating today's youth for their crude taste in humor, right before the ceiling collapses and showers him in the girl's excrement.
Hollywood Homely: Parodied In-Universe. Jake, the popular jock, has to make Janey beautiful because... you know, she's hideous! Just look at the glasses! And her ponytail! And the paint-covered overalls! And this in comparison to an albino hippy, a hunchback, and conjoined twins.
Informed Ability: Parodied. Janey's "artistic talent" is essentially just drawing kindergarden-level stick figures. It's a bit strange how she draws them with wild, violent Jackson Pollack-like techniques, though.
Meta Guy: Most everyone, but the two most consistently aware of the genre conventions are Malik and the unnamed tour guide played by a pre-How I Met Your Mother Josh Radnor "Who would have guessed this school was filled with professional dancers?"
Non-Specifically Foreign: "European" is about as close as you're gonna get with Areola. While saying "grazie" when Janey complimented her backpack might lead you to Italian, her accent changes with every scene.
Silent Whisper: Austin whispers into Janey's ear, causing Jake to launch into a hysterical confession. Austin then explains to Jake that what he actually whispered into Janie's ear was that Jake was about to launch into a hysterical confession, thus reaffirming everything he just whispered into her ear.
Sophisticated as Hell: The Token Black Guy is revealed to be this, delivering a very deep and insightful speech to Jake near the end. When Jake pauses to thank him, then dashes out abruptly before he can reply, he says only one word: Motherfucker.
Spit-Trail Kiss: Between Jake's sister and an elderly woman pretending to be a teenager at the Wild Teen Party. Probably one of the grossest ones ever recorded on film.
Stock Character: This movie goes out of its way to include as many as possible, usually directly referencing the more famous examples from this genre. Lots of Lampshading too.
Unusually Uninteresting Sight: Areola again — outside of her introduction, and the other naked girl at the party who complains that she copied her outfit, no one notices her walking around in the buff.
Wild Teen Party: Parodied. They begin setting up the party as the parents are leaving.
Preston's Mother:[Preston's parents are just heading out for the weekend] Now Preston, I left some money on the kitchen counter. Oh and the emergency numbers are by the phone. Preston's Father: And remember son, no parties. Keg Guy:[Two guys walk by carring a beer keg] Keg comin' through! Hey Preston. Preston: Whats up, man? Preston's Father: We're really trusting you here, Preston. Roadie:[Behind them two more guys roll in a huge set of speakers] Where do you want these speakers set up, Preston? Preston: Yeah, just move all the shit in the dining room. [to his parents] Preston: Well, you guys really should hit the road, huh? Because I'm about to take your antique Ferrari to the inner-city to buy some hookers. Preston's Mother: Well, alright, sweetie. We'll call you later to check in. Preston: Oh, mom. By that point I'll be so high I won't even know where the phone is. Preston's Mother: Haha! That's my boy.