Continuity Nod/Live-Action TV

Examples of s in include:

"Davros: "Impossible. That face...after all these years." Sarah Jane: "Davros. It's been quite awhile. Sarah Jane Smith. Remember?" Davros: "Oh, this was meant to be. You were there on Skaro, at the very beginning of my creations!""
 * In The Big Bang Theory
 * Episode The Friendship Algorithm, Howard Wollowitz says he's thinking about growing a mustache and that George Clooney has one now. In The Electric Can Opener Fluctuation from the following season, he grows a giant beard while at the North Pole, then keeps the mustache, calling it "the Clooney."
 * Penny's Check Engine light
 * That one is more of a Running Gag
 * The flashback episode "The Staircase Implementation" had a few nods to previously-referenced plotpoints, such as Joyce Kim, Leonard's short-term girlfriend, and the former resident of Penny's apartment, a transvestite.
 * In "The Friendship Contraction", Howard refuses to take Sheldon to the model train store, a hobby he acquired in "The Pulled Groin Extrapolation".
 * The Batman cookie jar from "The Bat Jar Conjecture" can be seen on the kitchen counter in later episodes.
 * Likewise, the sword Longclaw that Leonard and Sheldon purchase in "The Russian Rocket Reaction" can be seen on their wall beside the door in following episodes.
 * iCarly: Despite the show's episodic plots relying on Status Quo Is God, combined by Nickelodeon airing them Out of Order, there are still a lot of elements within the show's universe that nod to episodes from early in the show's timeline: Spencer's sculptures often stick around on set, including the hammer that almost killed Carly staying lodged in the wall, the iCarly iWeb trophy in the studio, and Freddie's giant pie spycam from way back in Season 1.
 * iThink They Kissed is a very good example. The interrogation scene between Carly and Freddie recalls plots from a lot of previous episodes: iKiss, iPromise Not To Tell, where Carly overpowered Freddie, iSaw Him First which referred to when Freddie's voice got lower, and iTwins, with Freddie still not believing that Melanie really exists.
 * iBeat the Heat guest stars the residents of Bushwell who had appeared in earlier episodes, among whom are Chuck, Griffin, Mr. Klemish, Dr. Dresdin and Lewbert, who even had hilarious dialogues with Mrs. Benson involving their failed relationship.
 * In iPsycho, Spencer tells Gibby that he got kicked out of sleep-away camp, but doesn't say why. In the earlier episode iTwins, he consoles Freddie about the "Clown Day" incident by telling about how the other campers tricked him into thinking it was "Naked Day."
 * Caprica occasionally does this, oddly enough most often through musical notes, such as using the Adama family theme during Tamara's funeral. There's also, of course, the "by your command" line from at the end of the pilot, which is itself also a Mythology Gag for the old show.
 * Several on the new Doctor Who series:
 * In "World War Three", when Harriet Jones asks the Doctor about his Northern accent, Rose answers (as the Doctor answered Rose when she first asked him about it), "Lots of planets have a north."
 * "Dalek": Several of the Doctor's enemies from the old show are on display in an underground museum.
 * "Bad Wolf": The Face of Boe is described as the oldest inhabitant of the Isop galaxy. The Isop galaxy was the setting of the William Hartnell story The Web Planet.
 * In the same episode, the security guards on the Game Station threaten to send the Doctor to the Lunar Penal Colony, a direct reference to the Third Doctor story Frontier in Space, in which the Doctor really does get trapped on the Colony.
 * And both "Bad Wolf" and "Parting of the Ways" had a transporter that left behind what appeared to be ash, echoing "The Twin Dilemma".
 * In "The Satan Pit", the Doctor mentions the inhabitants of Daemos, attributed in "The Daemons" as the source of demonic imagery in human mythology, among the races who share similar Satan-like characters in their mythologies.
 * In "Tooth and Claw", the Tenth Doctor arrives in 19th-century Scotland and uses "Dr. James McCrimmon" as his alias. Jamie McCrimmon was one of the Second Doctor's companions, hailing from 18th-century Scotland.
 * In a hilarious Continuity Nod In-Joke, in the Series 4 episode "The Poison Sky", when the Doctor is given a Gas Mask by the UNIT General, the Doctor remarks "Are you my Mummy?".
 * From the same episodes in Series 1, Jack Harkness mentions Pompeii and uses the phrase "volcano day." The Doctor uses the phrase again in "Fires of Pompeii" when he and Donna figure out where they've landed.
 * At the end of "Turn Left", Rose's appearance and the upcoming danger is heralded by the words "Bad Wolf" appearing everywhere the Doctor looks. This is a shout out to the ongoing mystery of the first series, the repeated words Bad Wolf appearing everywhere they went, but not with nearly as much frequency.
 * Obscure one: In Destiny of the Daleks (Tom Baker era, late 70s), quoth Davros: "Doctor, do you believe your puny efforts can change the course of destiny? ... Destiny, Doctor.... Invincible necessity.... Power. My power. My invincibility. My supreme plan to control the universe... Errors of the past will be rectified. I will add new design elements to the Daleks' circuitry. They will be armed with new weaponry. Weaponry so devastating that all matter will succumb to its power! I will equip them with all the knowledge of the universe! ... The Daleks NEED ME!"—In "The Stolen Earth"/"Journey's End" at the end of season 30 (aka Series 4 in the new ordering), Davros
 * Probably the longest delay before a continuity nod, in "The Stolen Earth" the Doctor mentions, "Someone tried to move the Earth before, but that was a long time ago...", calling back to the Hartnell era in which  (If you wondered, 45 years. 45 years!)
 * From the immediately following episode "Journey's End":

"Martha: Wait a minute--there was an earthquake in Cardiff a couple of years ago. Was that you? Tenth Doctor: Oh, that was a long time ago. I was a completely different man back then."
 * Not as far reaching as most of the above, but in the finale of season 4, the Doctor and Rose ask if Gwen from the Torchwood team has a family history in Cardiff. She says that she does, going "back to the 1800s," indicating that the character Gwynneth from "The Unquiet Dead", played by the same actress, shared "spacial genetic multiplicity" with Gwen's family.
 * "Voyage of the Damned" nods to the previous two Christmas Episodes by having everyone realize that London isn't a good place to be on Christmas unless you like being at ground zero of an alien invasion.
 * So at the conclusion of The End of Time, the Tenth Doctor is about to regenerate into Matt Smith and say his last goodbyes to his companions over the years. And then there's Alonso from "Voyage of the Damned". And THEN there's the great-granddaughter of Nurse Redfern "Human Nature"/"The Family of Blood".
 * His good bye to Alonso is both nice and a bit thoughtless. He hooks Captain Jack Harkness up with Alonso. However, the scene becomes alot darker if you know why Jack is there and not with Torchwood at the time.
 * In "School Reunion", Rose argues at companion from the 1970s (or the 1980s) Sarah Jane over who faced the toughest aliens and monsters, referencing actual episodes of the classic and new series, including the previous week's.
 * During The Sarah Jane Adventures, when she first encounters the Slitheen, Sarah Jane remembers that argument, saying aloud, "Slitheen in Downing Street". The Slitheen also mention their routine job where the family members never came back.
 * At the beginning of "Utopia," there's a mention of the events of "Boom Town" (the last time the TARDIS had to refuel in Cardiff) and the Ninth Doctor:

"Napoleon Solo: Very ingenious. Am I to assume I'm in THRUSH Headquarters? Oregano: When we reach the 13th floor. Napoleon Solo: Mmm. That haberdashery shop... Oregano: What about it? Napoleon Solo: It's quite impressive. I wish U.N.C.L.E. could afford that."
 * In the next episodes continuing the story of "Utopia,"  offers his wife a jelly baby. A bit of an Ironic Echo as well.   also mentions the Doctor fighting off Sea Devils and Axos, both from Jon Pertwee's tenure in The Sea Devils and The Claws of Axos.
 * The 11th Doctor's fez-and-mop combination mimics Seven in Silver Nemesis.
 * Quite possibly the biggest continuity nods are to the other doctors. The biggest one ever was when The Eleventh Doctor is facing the Atraxi in the Series 5 premier and asks them if the Earth is protected. The Atraxi looks at all the various monsters that show up in the series (including those that don't attack earth), then the Doctor asks "What happened to them?" Cue a twenty second montage of every single Doctor from William Hartnell to David Tennant with Matt Smith walking through the image of Tennant to say "Hello. I'm the Doctor."
 * Buffy the Vampire Slayer:
 * One of Xander's roles on the show (possibly an aspect of his role as the "heart" of the team) was pointing out the similarities of their current situation to plots from the past.
 * In Buffy's Season 2 finale, Willow is going to attempt to restore Angelus's soul. Xander comes to Buffy knowing this, but he chooses to lie, telling Buffy that Willow said to "Kick his ass." Nothing is made of this until five years later, on a Season 7 episode, Buffy refers to the "Kick his ass" message in front of Willow and Xander. Willow indignantly denies the allegation, Xander glosses over the awkward moment, the subject is changed and nothing is said of it again.
 * In the second series episode "Phases", Oz remarks, while looking in the school's trophy cabinet, that the eyes of one of the statues seem to follow you wherever you go. This is a direct reference to series 1 episode 3 where the spirit of a witch was - unbeknownst to the characters - trapped inside said statue.
 * In the Season 6 episode "Hell's Bells," when Willow talks to Xander, both decked out in a dress and tux, respectively, she remarks it's a good thing she realized she was gay because of their actions in formal wear, referencing Season 3's "Homecoming" and the resulting arc.
 * The Season 8 comic-book continuation (outlined and written in part by Joss Whedon) goes as far as to reference events that happened on Angel final season. One of them retconned the fact that Buffy was dating a vampire called the Immortal.  The other is less justified, as it involves Buffy making reference to something she never appeared to know on the series, though she could have learned it by Andrew in the meantime:.
 * In the Season Seven episode "Him", Buffy tries to kill Principal Wood with the rocket launcher she used to kill the Judge back in Season Two.
 * In the same episode, Willow mentions the danger of love spells. Xander has a brief flashback to a season two episode in which all the girls in Sunnydale (save Cordelia) fell in love with him due to a love spell.
 * Don't know if it's intentional or not but Xander wears a particularly "nice shirt" in season one that Oz wears in season three. There's a Slash Fic series that explains the backstory for the transfer.
 * When Willow and Oz meet for the first time, Oz only says one thing: "Canapé?" and offers her a plate of it. When Oz and Bayarmaa meet for the first time, Bayarmaa only asks, "Butter tea?" and offers him a plate of it.
 * Angel, as a Spin-Off of Buffy the Vampire Slayer, occasionally included Continuity Nods to its parent show. One good example was an episode where Angel tracked a girl with Telekinesis who accidentally TKed a steel rebar into his chest. Being a vampire, that didn't kill him, but the pain distracted him enough that he didn't get any information on the girl, not even her name, before she ran off, making helping her difficult. When Cordelia chastises him for it he says "Do you know how hard it is to think straight when you've got a steel rebar embedded in your torso?". She thinks for a second then says "Actually, I do. Benefits of a Sunnydale education". This is a continuity nod, referencing an accident the character had two and a half years ago on a different show, and also a Development Gag: Charisma Carpenter, the actress playing Cordelia, really does know the feeling, she was impaled herself in real-life and the scene was written into Buffy to explain the scar.
 * Angel also has several episodes featuring a woman named "Anne" who works with the homeless. The character actually originated in a season two episode of Buffy as a wannabe vampire named Chanterelle. She shows up again in a third season episode (in which Buffy runs away to Los Angeles and gets a job as a waitress, calling herself by her middle name, "Anne") and is now going by the name Lily. By the end of that episode, "Lily" has adopted the fake name—and job, and apartment—that Buffy has been using, and Buffy returns to Sunnydale. Angel and company are, of course, unaware that Anne is using a fake name taken from Buffy during her brief stint as a runaway.
 * The Cosby Show and its Spin-Off A Different World maintained close continuity ties even after Lisa Bonet left the latter program. Dwayne Wayne once visited the Huxtable home, and a former regular character from The Cosby Show, Charmaine Brown (played by Karen Malina White), showed up on A Different World as a new student at Hillman College.
 * Arrested Development does this very frequently, one of the reasons it is much admired by fans.
 * Third Watch's finale had a photo in the background reporting on events a few years previously, when Ty Davis Jr. helped save lives during a blackout.
 * The HBO series The Wire may be one of the most consistent examples of this trope, going out of its way to reference events and characters from multiple seasons past. Notable examples include: Drug dealer Bodie Broadus referencing a conversation from the beginning of the series when talking to a detective in the fourth season; a former chauffeur named Day-Day being brought in to testify against a senator in the fifth season (after his last appearance was in the first season);, a small boy who was seen trying to emulate his target two seasons prior to the episode; the main criminal organization of the second season (The Greeks) show up again in the final season to do business with drug baron Marlo Stanfield...the list goes on.
 * An addict first appears in Season 3 as a clean-cut college student buying drugs in Hamsterdam. In Season 4, she is seen talking to Old Face Andre, now obviously a streetwalker. And finally in Season 5, she appears in order to give a speech at a Narcotics Anonymous Meeting.
 * And that's not even mentioning the string of characters from seasons past that made brief appearances in the fifth season even if they didn't have major bearing on the season's plot themselves, including but not limited to Nick Sobotka, Clarence Royce, Randy Wagstaff, and Wee-Bey Brice.
 * The Degrassi franchise does this, most notably in its current incarnation, Degrassi the Next Generation. The pilot episode, and many of the scenes involving adults that come later on in the series, are continuity nods. Joey Jeremiah owns a car dealership (he was obsessed with vehicles in Degrassi High), and other characters make cameo appearances (some of which are still affected by events that happened in previous series, like Lucy).
 * Lost has featured several of these, such as allusions to the polar bear in the pilot episode. The episode "Exposé" was essentially one big long Continuity Nod.
 * In the 2008 season opening of NCIS, Tony has been assigned to the (fictional) aircraft carrier Seahawk. The Seahawk was a recurring location on JAG, including being the location of the Pilot Movie. NCIS is, of course, a Spin-Off of JAG.
 * Stargate SG-1 has plenty, ranging from the blatant (anytime Carter's reminded that she blew up a sun) to the very subtle (Jackson always looks a little uncomfortable when someone mentions radiation).
 * After being transformed into a teenager In the episode "Fragile Balance" Col. Jack O'Neill does not convince the others of his identity even after revealing classified information only he could know. Daniel Jackson reluctantly admits stranger things have happened, at which point he is asked to name one. He names several before being interrupted, "well there was that one time we became really old, the time we became cavemen, the time we all swapped bodies..."
 * Other notable nods include: macaroons (in the last two seasons and the films), Vala's first appearance, the time Daniel replied to a question about whether or not he was a Soviet spy in Russian (to be fair, the question was asked in Russian too), the numerous alternate timeline and alternate reality episodes, and "undomesticated equines".
 * The last one is actually referenced repeatedly in-series as being a "callback" to what may have been Teal'c's first joke. It goes so far that it's even mentioned in Atlantis when Sam crosses over.
 * Star Trek Enterprise was practically built around this concept. Considering its status as a prequel, most episodes revolved around the minute facts surrounding the future events like the forming of the Federation. Some range to really excellent uses like the first practical use of the force field and Brent Spiner as a distant Mad Scientist relative of Data's creator, to some groaners like a discussion on the probability of Vulcan/Human hybrids.
 * Turned up on several other Star Trek series' as well. For example, Tom Paris on Star Trek Voyager referencing the Dixon Hill series, Picard's favorite holonovel from Star Trek the Next Generation.
 * In The Next Generation, Worf helps Keiko deliver Molly. When he hears that Keiko is having another baby in DS9, he takes care to be far away when it happens. Very far. "Visiting his adopted parents on Earth"-far.
 * Criminal Minds makes extensive use of this as Character Development—Garcia's fear of being outside her office, Hotch looking at his phone out of habit, and Garcia and Morgan's relationship being prime examples. The casual viewer would completely miss all this without it affecting the story too much.
 * The Seinfeld episode "The Andrea Doria" features George telling a condo board his entire life story to arouse their sympathy so they'll give him an apartment. Naturally, it consists entirely of references to previous episodes.
 * In the episode "The Puffy Shirt," when George becomes a hand model, he says "I won a contest" to prove that he is Master of his Domain, a reference to "The Contest."
 * Also in reference to "the Contest", in the episode "The Handicap Spot," George can be seen reading a Glamour magazine in the background at his parents' house. In "The Contest," he was caught by his mother doing that with her Glamour.
 * In the finale, when their plane starts falling and they think they're going to die, George admits that he cheated in the contest.
 * In the House episode "Painless", a man walks to the conference room, and asks which one is House. House says: "The big black guy". Later, he tells to Foreman: "Can you blame me? The last time that happened, the guy shot me"—a reference to the episode "No Reason" (though then, he answered "Skinny brunette" to the same question, and it didn't help him).
 * In "The Itch", the Patient of the Week became agoraphobic after he was mugged. House comments: "Anybody can hate humanity after getting shot. Takes a big man to hate it beforehand." This also can be interpreted as a reference to "No Reason".
 * Used every now and then on How I Met Your Mother. For example with the saluting to things like "private matter", "general idea" and "major clean up".
 * A particular favorite of mine: Barney makes a throwaway reference in one episode to having had sex with Madeleine Albright. In a later episode when we see several of his conquests flash before his eyes, Albright is among them.
 * Another great one was the throwaway reference to Stella's husband, Tony, moving to LA to become a screenwriter. A season later, a movie he wrote based on Ted's life becomes the center of an episode.
 * In an early episode, Barney and Ted's first meeting is shown with Barney stating that they "just met at the urinal". A later episode extends the flashback, showing that the pair did indeed meet at a urinal.
 * In a season 2 episode, Barney reveals that he lost his virginity to a middle-aged neighbor. In season 3, a chance encounter with the woman who plucked his flower results in him losing his mojo.
 * The dating service that couldn't find a match for Ted in season 1 returns with a match later that season, although
 * Law and Order:
 * Jack McCoy goes after a John Yoo-like figure for war crimes. When he's called on it, he mentions a previous episode where he prosecuted a Chilean general for war crimes.
 * In an earlier example, in the episode "Jeopardy," a judge facing charges of taking a bribe - a sweetheart deal on a mortgage on his house in Sand's Point in exchange for favorable rulings in the case of the son of a family friend - commits suicide. Two seasons later, in "Harvest," McCoy makes a reference to a doctor/defendant having a large financial obligation in the form of a mortgage on a house in Sand's Point that he bought from a judge's widow. There's no direct connection made, but alert fans picked up on it right away.
 * Psych does this on multiple occasions, including references to "Chad," the character Shawn played on a telenovela in an early episode.
 * In Mr Monk Gets Cabin Fever, Natalie mentions that people seem to die wherever Monk goes. Stottlemeyer agrees with her, citing a few different Busman's Holiday incidents involving Monk, all of which were previous episodes of the show.
 * In Mr. Monk and the Lady Next Door Monk becomes despaired when he realizes that everyone who quickly becomes a close friend of his is just doing it to get something, recalling how frequently they turn out to the be villain of the episode. Needless to say, this time
 * An interesting case of a literal Continuity Nod on Iron Chef America: in the opening, the Chairman nods in respect to a yellow bell pepper-the symbol of his uncle and predecessor, Chairman Kaga.
 * Used pretty frequently on ER. But then, with 15 seasons, the show has a lot of backstory to refer to.
 * The recent CSI crossover gives us a very nice continuity nod in its first part. When Ray Langston arrives in Miami, Horatio Caine asks him to give his regards to Catherine Willows and gives condolences for the loss of Warrick Brown (both characters traveled to Miami and worked with Horatio in the CSI episode which served as Miami's pilot). Similarly, in the final episode of the crossover, Ray gets texts from both Horatio and Mac Taylor, informing him of arrests related to his case.
 * CSI itself also had smaller continuity nods, recalling events from the first and second seasons in the ninth and tenth - a comatose rape victim and the adopted son of an early recurring foe respectively.
 * In the third season The Man from U.N.C.L.E. episode "The Hula Doll Affair", the entrance to THRUSH Headquarters in New York is an upper-class haberdashery, in contrast to the working-class Del Floria's Tailor Shop which serves as the entrance to U.N.C.L.E. Headquarters. Solo, as he is captured by Oregano (a THRUSH operative), remarks on the contrast:

"Parker: Remember last time I was the carrot? Remember how I stabbed that guy?"
 * Supernatural: Sometime offscreen third season, the Winchester brothers each got a possession-blocking protective tattoo. From that first appearance onward, the tattoos can be seen from time to time over the collar of their shirts, though attention is almost never drawn to them again.
 * Red Dwarf: In "Demons and Angels", whilst testing the food on the 'high' Red Dwarf, Lister refers back to several previous episodes: "I've been to a parallel universe, I've seen time running backwards, I've played pool with planets and I've given birth to twins, but I never thought I'd taste an edible Pot Noodle."
 * Of course, he's also made disparaging references to Pot Noodles before - notably in "Marooned".
 * This is rather a contested issue. In the episode guide, it points out that when Lister did play pool with planets, it was to divert a timeline that had gone wrong and after filling the black hole the timeline adjusted itself so the episode, in effect never happened. It may of course be, however, according to the episode guide at least, that Lister played pool with planets again and lived to remember it - but it wasn't thought worthy of another episode being written to honour this escapade.
 * Bottom: the Sprouts that did not get eaten in Holly make a reappearance in Terror.
 * Scrubs had a huge example in the big Musical Episode. In Carla's song, "For the Last Time, I'm Dominican", she reprimands Turk for mistaking her for Puerto Rican and asks him questions about herself. These questions are all references to previous episodes.
 * "Did I grow up in Illinois or was it Michigan?": In the episode "My Day Off", JD asks Carla something about her "homeland". She tells him she was born in Chicago.
 * "How long before we met was I in medicine?": In the episode "My Nickname", Carla reveals she had been in medicine for nine years before this first season episode. Turk and Carla met in the first episode of the first season.
 * "Was our wedding song the Beatles or Led Zeppelin?": In the episode "My Best Friend's Wedding", Ted and his acapella band, the Worthless Peons, sing the Beatles' "Eight Days a Week" at Carla and Turk's wedding.
 * In the third episode of Thirty Rock, Liz chokes on something she's eating in her apartment and manages to clear her airway by pushing a chair into her gut. In the third season, she starts choking on a date with a doctor so incompetent he doesn't know the Heimlich maneuver, and she does the exact same thing.
 * Castle's first episode of the third season has a callback to the first season (also the opening credits), when Ryan comments on a cardboard cutout of Castle that "He really is ruggedly handsome".
 * Later in the third season (3x10), they find a massive cache of Prohibition era liquor. Nine episodes later, a DA mentions that he just got a bottle of that stash.
 * And then, of course, when things get really hairy, Castle pulls out his custom-made bulletproof vest labeled "Writer".
 * When Marcel the monkey is introduced in Friends, he's sitting on Ross' neck and Chandler remarks "Hey, that monkey's got a Ross on his ass." Several seasons later, when Ross has a strange growth on his posterior region of which even the doctors don't know what it is, Joey suggests that it's something new that might be called for him as in "Poor guy, he's got a Ross."
 * Also in an early episode Chandler mentions he used to have a "Flock of Seagulls" haircut. In a S10 flashback Chandler is seen with a "Flock of Seagulls" haircut
 * Leverage throws these out on occasion. For example, an episode in season one involved Parker getting angry with the mark she was talking to, stabbing him with a fork and jumping out the window. Near the end of season three Nate is walking with her to catch up with the mark on a different con, about which Parker is a little worried.

"Doggett: You ever carry one of these? Scully: ...never."
 * It's also mentioned in Season Four's "The Fifteen Minute Job" when Parker gets excited with her performance after talking with the mark and exclaims "And I didn't even stab him!"
 * Donna and Ringo's wedding in Neighbours is accompanied by Sam Clark's cover of Angry Andereson's "Suddenly". Ringo tells him that Paul put him on to it, having heard it at his brother's wedding years ago. This was, in fact, the song played over Scott and Charlene's wedding in 1987.
 * During the first episode of 3rd Rock from the Sun, the main characters express a fear of Jell-O. When Sally is hospitalized, a nurse comes to visit the crew with Jell-O. Their reaction? Extreme horror.
 * The X-Files has a fair few in its 9 season run...
 * In one episode involving a man killed in a locked room, Scully examines a small ventilation grate, causing someone to ask "You don't think anyone could have squeezed through there, do you?". This is a reference to Eugene Victor Tooms, who killed people in locked rooms by doing just that in an earlier episode. The episode he first appeared in was even called 'Squeeze'.
 * In the episode 'The Field Where I Died', Scully tells Mulder that she wouldn't change a day of their time together - "Except for that Flukeman thing. I could have lived without that just fine." The Flukeman was a well known monster of the week from season two.
 * In 'Dreamland' events occur (which are later forgotten by everyone) in which Mulder's apartment is completely refurnished, acting as a comedic stinger at the end of the show. Several episodes later in 'Monday' his waterbed becomes a plot point, and he's unable to tell anyone why he has a waterbed. "I...I think it was a gift."
 * In 'Patience', one of the first episodes of season 8, where Scully works with new agent John Doggett, they go into a dark attic. Doggett produces a flashlight...

"It's the Mystic Mother! She was known as Rita during the Dark Times."
 * In the second season finale of Modern Family ("The One That Got Away"), Alex and Haley are preparing a video card for Jay with interviews done during the past year. Each of the interviews references a different event from the past season.
 * "Tony's mug" in Twenty Four. In the first season, Tony Almeida is often seen drinking from a mug with a Chicago Cubs logo on the side. It appeared infrequently throughout the first three seasons, and even had a bizarre online fan following. Following Tony's return in season 4, it's revealed that the mug is one of the few things he still has from CTU (used for comedy purposes; he drinks beer from it). The fifth season takes this a step farther and references the mug again when it's smashed after.
 * The "Jack Sack", the Fan Nickname for Jack Bauer's messenger bag he carries in the later seasons. Despite Jack being kidnapped and tortured in the interim between seasons five and six, and moving from Los Angeles to Washington (and then to New York), the messenger bag pops up from time to time throughout the series when Jack is on missions, and conceivably carries anything and everything.
 * When dies at the beginning of Season 5, Jack goes to the crime scene during the next episode, and sees the body lying on the floor of his penthouse suite. The camera focuses on his right hand, which still has the scarring from when he was.
 * Jack's arm tattoo (which he received prior to the events of season 3, when he was undercover in the Salazar cartel) is seen a handful of times throughout the rest of the series, most noticeably in a season-four episode where Jack changes his shirt after an interrogation.
 * In the Community episode "Modern Warfare", Abed's bandoleer of paintball pellets has a slot for his lip balm which is a reference to the earlier Halloween Episode. Also, a seemingly irrelevant scene involving Abed delivering a baby to a nameless character in the background of a random episode leads into him deliver another baby many episodes later. Lampshaded by him, of course.
 * Community is chock full of these. Not only do random secondary characters regularly show up in background scenes, speak a few lines, or get mentioned, but seemingly irrelevant scenes like Abed helping deliver a baby to a nameless character in the background of a random episode helps him deliver another baby many episodes later. Lampshaded by him, of course.
 * In one episode of Home Improvement, Tim soups up a power washer and blasts "Al's a gal" into a wall of the studio building. It's there every time Tool Time does a show outside at that location.
 * In Power Rangers Mystic Force, Mystic Mother is the same character as Rita, in reference to a stock footage character played by, and in tribute to Machiko "Rita Repulsa" Soga:


 * The Waltons: In an episode Jim Bob thinks he's adopted because he doesn't resemble other Waltons physically. Elizabeth conducts a school poll asking students whom they think Jim Bob resembles. One student's answer was, "a turtle". Much later in the series, the Walton boys are dressing for an event, and while Ben and Jim Bob are looking in the mirror, Ben ribs Jim-Bob by snarking, "Elizabeth's right. You do look like a turtle!"
 * Power Rangers in Space had a Badass Long Hair Red Ranger kill Zordon. No doubt this was a previous Red Ranger's greatest fear.
 * Surprisingly for a show that wasn't famed for its continuity, Charmed had a few, particularly in the eighth season.
 * Greg, Piper's one-off boyfriend from season 6 makes a guest appearance when Piper backs her car into him.
 * The Avatars from the seventh season and the Angel of Destiny (played by a different actor) from season four were called on for advice.
 * Billie mentions the sisters' actions in the season 2 episode "Ex Libris" and gets them to use the same tactic again.
 * In "Morality Bites" the spell to go to the future can only be used once. Later on in "Chris Crossed" (four seasons later) Chris says that there is no spell to send someone forward in time (the sisters had already used it so it had disappeared from the Book of Shadows).
 * Later Mash episodes occasionally include mentions of such departed characters as Henry, Trapper, Frank, and Radar.
 * Boy Meets World had a few, including the brief reappearance in season 5 of Shawn's pet pig "Little Corey" from season 3. There were also several references throughout the series to the time Shawn blew up a mailbox in season one.
 * In Torchwood: Miracle Day Jack at one point introduces himself as Dr. Owen Harper. Owen was killed in "End of Days". He was also a doctor before he joined Torchwood.
 * Several characters also reference the 456 Directives, which were adopted after the world-wide incident with the aliens only known as the 456 in the third series.
 * Gwen mentions she wishes the Miracle happened a year ago, so that Ianto wouldn't have been killed by the 456.
 * Done oh so many times on Warehouse 13, usually involving past experiences with artifacts. Some of these reference past episodes, others are Noodle Incidents, such as the one with Abraham Lincoln's hat, causing Pete to have an irresistible urge to free Mrs. Frederic. She was not amused.
 * In The Vampire Diaries Damon hid the moonstone (an enchanted stone which looked a bit like a fancy soap) in the soap dish, where it was promptly found by Katherine the next time she washed her hands, leading to some amusement at his terrible attempt at Hidden in Plain Sight. A season later Caroline is searching for Elena's necklace in the same room, and the show provides a close shot of her digging through the soap dish. This time, all it contains is soap.
 * Another nod to this is when Damon is hiding stakes with his fire wood and Alaric comments on how he should've learnt his lesson from the moonstone in the soap dish.