Only people that are relevant to the plot or a sidequest will be blessed with names. Everyone else will be nameless or be referred to with generic or descriptive titles.
For example, if the town guard is named Samuel Winthrop, you should probably make a mental note of him, as he'll very likely wind up being essential to your progress. If his name is Town Guard, however, you can safely ignore him, as he is superfluous and has no bearing on anything. At most, he'll provide some useful exposition, but it's guaranteed that he'll never need to be sought out again.
From a gameplay standpoint, this makes perfect sense and may even be a Justified Trope. By only giving important people names, you can reasonably narrow down the people you need to talk to, which curtails much of the tedium of having to Talk to Everyone.
A common exception that proves the desirability of the rule is when early non-important NPC's have names and faces, but the writers start running out of time or patience and just put in generic people later.
This is the naming equivalent of You ALL Look Familiar, and it is caused by The Law of Conservation of Detail. Contrast with The Dead Have Names (where characters are named poshumously to memorialize them) and He Had a Name (where a dead character's name is invoked specifically to send the message that the deceased wasn't just a bit of meaningless backdrop).
Video game examples:
open/close all folders
Played straight in many The Legend of Zelda games, where the people with unique names and character designs usually have a good chance of being one of the sages you need to rescue/assist later in the story. It's most noticeable in The Legend of Zelda: A Link Between Worlds, where literally every uniquely named/designed character you meet in your travels turns out to be a sage in the second half of the game.
Ōkami gives names to most of the characters, as well as a small introduction sequence and their name on a briefly appearing scroll. Even some of the monsters have personal names and titles, and there's also "Newly Dubbed: Sleepy", a bear who is, you guessed it, sleepy.
Thoroughly averted in The Godfather. Everyone has a name, which you can see by targeting them, so you won't be figuring out importance by name here.
Spyro the Dragon series: Every NPC and collectable has a name but the enemies, at least usually, don't seem to. Justifiable in at least the first game, as they were actually made out of gems.
Kind of done in both the 2D and 3D Super Mario Bros. series platform games. You know whether a character will be important or a boss if their name is in the level/mission title. No guesses who the boss is in Bowser's, Roy's or [other boss name]'s Castle or Fortress. Similarly, it's fairly obvious a mission title like 'Big Bob-omb on the Summit', 'Gooper Blooper Breaks Out', or 'Kingfin's Fearsome Waters' will have you battle a character with said name and you'll at least get a star/shine sprite for doing so.
Even in the character-based Ace Attorney series, there are some characters who do have sprites, but no known names, most obviously the Judge. Of course, any character with a sprite will end up being relevant to a case eventually - even the unnamed Bellboy in the series' second case. There are also characters who are rarely referred to by their names, but have them nonetheless (such as Penny Nichols from the first game's third case), but even they tend to have a piece of information you'll need to know.
Hype The Time Quest averts this by going out of its way to name almost all the NPCs, down to Maliq, a one-off thug who attacks you. Though there is the exception of a few guards and an executioner.
When talking to one of the characters in the flash game Nicholas' Weird Adventure 2, his character portrait doesn't show a picture; he just gets text from the author claiming the character is not important enough to take the time to make a portrait of him. As the discussion goes on, the author changes his mind and adds one.
Yume Nikki: Aside from the Effects and Madotsuki herself, absolutely nothing is named. Despite this, Fan Nicknames have been created for just about everything, and are almost universally accepted as their true names, such as "Uboa" for a particularly memorable Jump Scare character.
In Soul Calibur 3's "Chronicles of the Sword" mode, a lot of Elite Mooks on the field are named, but all that comes of the names is a strength boost. Regular soldiers just go by the name of their banner.
First Person Shooter
In the expansion to Star Trek Voyager: Elite Force the player expands his/her arsenal with a tricorder, which can, among other things, be used to scan various NPCs. In keeping with the series' Red Shirt tradition, important NPCs appear with their name intact, while others are simply called "crewman" by the device.
Regular enemies in the Ace Combat series are identified on the HUD simply with their aircraft model names. However, the rare ace pilots additionally have their callsigns appended to the plane model, marking them as priority targets, since they are usually much more dangerous than regular mooks. The Belkan War, which shifts the gameplay focus from blasting through nameless hordes to more personal one-on-one dogfights, takes this trope to the extreme, with 169 named enemy aces (more than the rest of the series combined), each of whom has a unique short biography unlocked after shooting him/her down.
TimeSplitters: Played straight in the first game, where only the player characters and a few of the joke characters get names, but averted in 2 and Future Perfect, where almost every random human Mook you fight in the story missions is given a name, and a few of them even get backstories and established personalities (although they can only be seen after unlocking them as playable characters). Future Perfecteven gave the zombies names.
World of Warcraft manages to avert this trope with most NPCs (except town guards), but there is no risk that you might mistake a NPC as more important: Those that have a quest for you have a golden "!" floating above them, and NPCs with important services have a subtitle such as <Flightmaster> or <Innkeeper>. Some minor NPCs don't even have any dialogue. Of course, most trash mobs still don't have names for practical reasons.
Averted in the Hobopolis clan dungeon in Kingdom of Loathing - all hobos have randomly generated names, and as most of them have one or more nicknames in addition to a first and last name, there are millions of possible combinations. This does result in occasionally fighting John Lennon.
Played straight in RuneScape. If you see a named NPC, then, even if they aren't plot important, they'll have some humorous interactions available or something. Unlike say, "Ardougne Guard" which you can attack, pickpocket or examine and that's it.
Star Wars: Galaxies initially averted this trope, in a sense, by having every single NPC in the game given a randomly generated name, for example, names would be like "Luke Skywalker (a farmboy)". However, not long after release, this feature was disabled as it made server start up after maintenance take too long.
Myth: The Fallen Lords and its sequels likewise avert this to give every living creature (i.e. excluding the undead and such who you wouldn't expect to have names at all) a unique name, and even allows you to rename the units under your command yourself; e.g. that warrior Malory with the 300 kills may just deserve to be called Malory the Great, a title he will carry down the levels for as long as he lives.
In ADOM, if you meet an otherwise normal monster or NPC with a name,they're either important to your quest, or a stronger-than-normal artifact guardian. Have fun figuring out which is which.
Dwarf Fortress: All the dwarves have names, as do any visiting humans and elves. But for the monsters to have names they have to slaughter enough dwarves to become important. As creatures which start out with names (dwarves, goblins, humans, etc.) rack up kills, they eventually gain an extension of their original name. Because of this, one can often tell who the local badasses are by looking at who has the longest name(s).
Something similar happens in Elona: any NPC related to a quest which is identical across all games will have the exact same name in all games. Shopkeepers, NPC adventures and townsfolk will have randomly selected names which vary from game to game.
Role Playing Game
In Final Fantasy IV, Yang is married. In early versions of the game, his wife's name was apparently "Yang's wife". Naturally, she is wholly unimportant to the plot. (Final Fantasy IV: The After Years gives her a proper name, Sheila, which makes it into the PSP version of Final Fantasy IV itself as well. She's still not particularly significant to the plot, though.)
Final Fantasy IV: The After Years zigzags this a bit. On the one hand, you get Player Mooks named "White Mage", "Black Mage", "Monk A/B/C", and "Guard A/B/C", who are about as significant as you'd expect. On the other, Ceodore spends all of his chapter and most of Kain's fighting alongside the Hooded Man (Kain's light side), and Rydia, Edge, and Luca wind up tagging along with the Man in Black (Golbez).
Final Fantasy Tactics totally averts this. With the exception of some random thieves and brigands, everyone with a speaking part in the many cutscenes gets not only a name, individual character portrait and sprite, but also a several-page-long biography detailing their lives and connections to the plot. Not only you never get to actually meet the grand majority of these people, most of them are thoroughly unimportant, die in their introductory scene or just plain don't ever show up at all and are just referred to.
Final Fantasy IX, Played straight and almost Deconstructed with the Black Mages, who are all named numbers, being mass produced. Even after they gain sentience, they still refer to each other as #86 or #147. Even the leader is #288. Only Vivi has an actual name, and learning about the Black Mages, goes through an existential crisis as he wonders if he too has a number.
Early on in Final Fantasy XIII, you know that Hope's mother isn't gonna make it out of the prologue when her introductory subtitle says only, "Mother." However, we later learn her name was Nora.
Fable II and Fable III do this with every random villager you meet. Every non or semi important/useful villager is given atleast a first name and a title depicting either their job(shop owners) or their role, housewife, villager etc.
Dragon Quest VIII, for example, only people that are important have names displayed in their dialogue boxes.
Lampshaded in Dragon Quest Monsters: Joker, where someone in the main town claims he is your rival, but then muses that you probably think of him as "some random blue-haired NPC."
Jade Empire. The Old Man might be an exception, though, since he's a quest giver with the name of "Old Man".
Oblivion and Skyrim partially avert this - most NPCs have unique names. There's still a lot of generic "Fire Mage"s & "Bandit Hedge Wizard"s.
Shadow Heartseveryone has a name which is also a capsule description of them. Not an actual name from the game, but an example of what this means would be "Nervous Man Monterey".
Lost Odyssey and Enchanted Arms use a capsule description as well. Scarily enough, Enchanted Arms uses this in a school that SCREAMS 'main setting of the game'... it's blown up before the prologue.
All three Star Ocean games do something similar; while some NPCs will have names, some will have just a title, while others will have both a title and a name.
In Fallout 2, some characters, - a fair share of the possible party members and the heads of most towns - have full voice acting and a 3-D pre-rendered face with close-up animation. The game's manual warns not to assume someone is important just because they have a face, or that someone isn't because they don't. That is mostly good advice, as the characters most likely to get a face are just the ones with the distinctive looks. In addition, it's often possible to determine which NPCs have some level of importance, either for a quest or simply the ability to converse with the player, by seeing if their description is different from most other NPCs.
PokÚmon has, since Gold & Silver, assigned names to each trainer you meet and gives you a cell phone so you can call them for repeat battles. No word yet why they call you every five hours to tell you about their adorable Metapod or a Vulpix that got away. Random Grunts for the local villainous team are typically left unnamed however. (With the exception of the Gamecube Games). The Diamond and Pearl Adventures Manga makes fun of this by having a recurring mook refer to himself solely by his assigned number: "K-2". (K-2 is pronounced similarly to "ketsu", or "butt". You can guess what his major identifying feature is...)
As in most RPGs, Baldur's Gate II has lots of unimportant characters without names, but provides something of a Lampshade Hanging when the following dialogue option pops up: "You are just a nameless observer. Of what use can you be to me?"
As mentioned above, Chrono Cross character portraits: with a note to the strange case of the Element shop owner in Termina who has a portrait and name but no real significance. In addition, Leena's portraited brother Una isn't important to the plot. On the flip side, Solt and Peppor, who are reasonably significant (certainly moreso than Lisa or Una), inexplicably lack portraits.
Averted in Last Scenario — every single NPC has a name (characters of any importance have portraits, though).
It's easy to figure out that Ms. Toriumi, your homeroom teacher in is actually Maya, the Hermit Social Link by virtue of the fact that she's the only female teacher with a character portrait.
On your first day at school, you can talk to several students as you make your way to the teachers office, some who have portraits and some who don't. Guess which ones end up being Social Links. (Though none of them are actually named until you start said Social Links)
In Persona 3 Portable you can have a strange conversation with a man who, while lacking a name (he's called "Man Drinking Alone", has his own Character Portrait. It was immediately assumed this man was an Early-Bird Cameo for an upcoming Atlus title. Cue cries of I Knew It when the game Catherine was revealed, starring the aforementioned man (whose real name is Vincent).
In Persona 4, a rather strange looking kid hits on Yukiko rather early in the game, and judging from his character portrait, you get the distinct impression that he becomes important later (and he does; he's a minor villain by the name of Mitsuo Kubo). The same could be said for Taro Nametame, who is introduced early on and, aside from having an affair with one of the victims, has nothing to do with the story until you find out he's the one who's been throwing people into the Midnight Channel. On the other hand, the gas station attendant lacks both a name and character portrait until after the big reveal in the true ending.
Planescape: Torment partially averts this at early stages of the game, as several NPCs in the Hive with generic descriptive names have nongeneric dialogue. For example, one gives you a ring she promised you for killing her husband, while another gives you a minor quest. However, they still have no bearing on the plot, for understandable reasons. There are also a few named ones that still don't do anything - no quests, no information, can't get anything from them. And, of course, the most important character, i.e. the protagonist, does not have a name at least, until the very end.
All the Wild AR Ms games give names to every single NPC; some even let you change their names!
Played with in Wild ARMs 5. Many of the NPC's give fetch quests. All of these NPC's are Shout Outs to the heroes of the first four Wild ARMs games, and all of them are identified with e.g. "Serious-Looking Drifter" rather than their actual names.
Averted to some extent in Dragon Age: Origins: The best example is with temporary party members - many people you can get in your party only for about ten minutes in one of the backstory/tutorial quests have tons of unique dialogue, their own battlecries/snarky lines they say when killing things, and in some cases well-developed backstories and personalities, making it impossible for you to tell who is in line for a Plotline Death. Of particular note are the other trainee Grey Wardens - there really is nothing that will give away the fact that Daveth and Ser Jory are sacrificial lambs while Alistair can be around for the entire rest of the game. Also Jowan, who you can very briefly have in your party, comes with not only his own battlecry, but several, many of which are funny. He's also one of the most three dimensional characters in the game. You can have him in your party for ten minutes, tops. There was an Aborted Arc in which he could join you, so that's probably why.
However, Dragon Age still has generic NPCs - 'Bandit', 'King's Guard', etc. Notably, the two unnamed NPCs who can help you reach the top of the Tower of Ishal are forgotten about the moment the PC is overwhelmed by darkspawn.
This makes collecting the 108 Stars in the Suikoden series a bit easier: Does the character have a portrait and a name? Congratulations, you've probably either met one of the villains or a star (or both). For the rare non-villainous characters who aren't stars Stars of Destiny? Don't worry, the game will generally clarify things pretty soon by killing them.
Played with where the citizens have amusing titles in the text boxes in place of names, such as "Man with A Frowning Face" or "Young Man Who Believes in Justice". This may also be used until you find out the person's name, such as with Rosalyn, who was listed as something along the lines of "Hero with A Parasol".
Down right Deconstructed during the final act. The Big Bad reveals that this world is a world where everything everything is governed by classification, esspecially people so that his daughter can live a life exactly the way she wants: full of adventure. The titles are the actual basis and programming for the character, with everyone just going along with what they are expected to do. This includes your team, from "Hero" Rosalyn who valiantly opposes everything bad and injustice, to "Eccentric Scientist" Kisling, who reserches ghosts and collects toe nail clippings. Everyone except Ari, who lacks a title and is such a deviant, someone who can force everyone out of their programming. And indeed, once we find this out, the team begins to break free of their descriptions. You can actually see the Foreshadowing, because the game has a wierd obsession with classifications.
Played straight in Summoner but averted in Summoner 2, in which everyone you spoke to had a name - except in the Realm of Twilight, in which everyone you can speak to has a title. This is because they actually don't have names, not just because you don't know or care about them. It's worth noting that there are far more NPCs in the first game than the second.
Averted for the residents of Tazmily in Mother 3, who each gets his or her own name despite many of them being completely unimportant. NPCs from other places, most notably New Pork City, are never named, but later on, you find out there's actually a rather good reason for it.
Averted for the most part in Anachronox. While guys like guards or monks usually have generic names, most NPCs you encounter in the game have specific names (or failing that, some sort of unique descriptive title).
Many of the Ys games, particularly, Ark of Naptishtim, Origin, and most remakes, avert this. Every character gets their own name regardless of their importance to the story. In some games, every character gets a character portrait as well.
Averted by Dragon's Dogma; every NPC in the Cast of Snowflakes has a unique name, even if they only get to spout the usual "Woe is me, the dragon shall eat us all!" random lines. They also have unique faces and can be romanced, though of course they don't have subplot sidequests like the "main" characters and their gift preferences are determined by where they live rather than being unique to them (travelers prefer stamina potions, Casardis men like steak, Gran Soren men like fish, and women prefer different types of flowers). The random bandits who attack you play this one straight, though, mostly because you can't talk to them and you only see someone's name when having a polite conversation.
Between all the non-plot important NPCs, there's a rather huge group of them that are named. They compensate their lack of plot importance by forming part of the global affinity chart and tending to play important roles in sidequests and sidequest arcs.
Mostly averted in Drakensang, where the only ones without a name are usually either mooks or citizens who have nothing to tell you anyway. An example is found in the Moorbridge Swamp: all the members of the militia patrolling the village are named, even when They attack you led by their crazy officer later.
In Xenogears, removing the Limiter of a character who has a name and portrait unlocks their ability to use top-tier attacks. But when the Limiters get removed on all of humanity...it turns out that nameless, no-portrait NPCs have an alarming tendency to transform into hideously mutated beasts. Good job, Heroes.
Shoot Em Up
The first six Touhou games never bothered to name or give the midbosses profiles. Later universe compendiums continue to act as though they don't exist. Which became somewhat frustrating when one of them recurred... into the only game that didn't include boss names or profiles.
The Stage 1 boss of Lotus Land Story is only known by the tag used for her in the coding, "orange". She technically does not have a name of her own, though she does have portraits.
Turn Based Strategy
In the Fire Emblem series, any named character appearing on the battle field is either an ally, a boss, recruitable, or vital to the plot in some other way. Everyone else is generic. However, all bosses have portraits and names, some can be recruited, most can't. Also, some characters have appeared with portraits despite being un-recruitable (to more or less screw with the player) such as Khosen the manekete and Heimler, both from FE1 and FE11.
Subverted in Disgaea: Hour of Darkness with a Sassy Demon named The Dark Adonis Vyers, er... Mid-Boss, dubbed such by Laharl because he deems him unimportant. His name even shows up as that on his text boxes. He's still important to the plot in the long run.
Subverted in Videogame/Disgaea2. Adell's mother is only referred to as "Mom", but is given full body-art and voiceovers like the rest of the main cast. She is also the one responsible for summoning the Overlord so that Adell can kick his ass.
Averted in Tactics Ogre, as all characters are named. While generic troops receive a random name from a pool, even one-off bosses have quite detailed entries in the Warren Report.
Averted in Battle for Wesnoth, in which any newly-recruited intelligent living unit will have a random name appropriate to its type assigned to it. (Undead and animals remain nameless by default, though Liches will retain the name they had as living wizards.)
Wide Open Sandbox
S.T.A.L.K.E.R. averts this as well, thanks to the fact that just about everyone in the game- friend or foe, and even dead bodies you come across that were planted specifically by the developers, rather than being killed by rival factions or hostile mutants- have first and last names. Most of these names in the U.S. version at least follow a strange convention, however- while the first name is usually something common to the region, such as Sergei or Vasilya, the last names are usually straight from the dictionary. Which is why it's always hilarious to see a guy named Max Dinosaur. It is because stalkers are given the first name and a nickname, not the last name. This is most likely a reference to the custom of organized criminals in Russia. On the other hand, soldiers in the Zone are referred to by their rank and last name.
Averted in Survival Crisis Z where every NPC is randomly generated, but all building owners have names, and your party members also get a randomly generated backstory (consisting of a name, job and hometown) that they will talk about if they survive long enough.
In the PC game Pathologic, all of the main characters and important side characters are given names, while minor characters are named by their description. In addition, when you talk to any of the characters, an icon with a black-and-white photo appears in the corner of the screen. With storyline characters, it's a person resembling the model. With random people, it's a creepy ragdoll.
Portal 2: At the end of the co-operative campaign, Atlas and P-Body discover a vault containing ten thousand more human subjects in suspended animation. But in the "Peer Review" DLC GLaDOS says she killed them all trying to make them as indestructible as Chell. Clearly, they weren't important to the plot.
An odd variation appears in Enemy 585 (by Nitrome). The only "named" character is Enemy 585, who was just another mook in a platformer than finished before the real game started (which was to rescue Enemy 585 after he was trapped in the boss' castle after the "game").
As demonstrated in Slowbeef's Let's Play, Amazon: Guardians of Eden consistently inverts this trope in a very odd manner: after the third chapter or so, it is almost guaranteed that important, speaking characters will go unnamed, but non-speaking and unimportant background characters will be given names and strangely elaborate backstories that the player character really has no way of knowing in the first place. This comes to a head with the shopkeeper that sells you items you need to finish the game - since they gave him a name, they go out of their way to Third-Person Person all of his interactions with you rather than letting him just talk to you.
Non-video game examples
In Haruhi Suzumiya, if anyone has a name, s/he will get involved in a plot in someway or another. If anyone has full name, watch that character, because without exception, they will have a supernatural power. Of note is that we never learn the narrator's name—"Kyon" is just a nickname that everyone uses.
Simoun averts the voiceover corollary in its first episode, which is narrated by a nameless Red Shirt pilot who dies (playing the main trope straight) in the episode's climax.
Project A-Ko parodies this by naming the three main characters like extras (at least, if you ignore their surnames).
One of the things that made Mobile Suit Gundam really stand out is that they played with this trope a lot, to often heartbreaking effect. Many enemy pilots got names and a bit of characterization, despite the fact they usually just ended up getting wasted by the Gundam in the end, anyway.
In Martian Successor Nadesico, Akito gets replaced by an unnamed female pilot about halfway into the series. No prizes for guessing what happens to her in her first fight.
In Not as Planned, the only characters with names are canon characters from The Lord of the Rings, such as Elrond. The girl who is the main character has no name in the story. She meets no named characters, except Elrond. This shows that the girl and her associates are not important persons.
In The Secret of NIMH, Jenner's henchman who has a Heel-Face Turn at the last minute is named Sullivan, although it's only visible in the credits. This is the name of director Don Bluth's business partner in making the film.
Brutus, however, doesn't actually serve much plot purpose, and fades into obscurity almost immediately after being given a name, save for a single shout-out towards the end that you will barely notice due to it being a muffled background noise.
Nigel Powers: Have you any idea how many anonymous henchmen I've killed? Look at you! You don't even have a name tag! You've got no chance. Why don't you just fall down? (The henchman falls down.)
In The Gamers: Dorkness Rising, the gaming group meets Random Peasant Here to Advance the Plot. When Daphne asks him his name, it's revealed that the GM hadn't bothered to give him one. He has to quickly do so.note It's Willam.
In a Russian pulp-fiction novel, the villain holds the hero at a blank point. He's not a cold blooded killer though and even confesses how relieved he is to know almost nothing about his victim, as killing someone you know even slightly is so much harder. The hero hastens to provide his comprehensive credentials, much to the villain's chagrin from such selfish indiscretion.
Inverted in Small Gods. At one point, a nameless Red Shirt is killed off, only for his name to be immediately revealed. He's still unimportant to the story though.
David Drake likes to subvert this and made extensive use of Tuckerization in one of his RCN books for this purpose (as well as to salute his friends). He explained this in the acknowledgments to the book and noted he was using the names but not the personalities and this was, in many cases, "a Good Thing" — because (he didn't spell this part out) some of the people he named after his friends were total wastes of skin.
Very averted in the Honor Harrington series. Weber has been known to introduce a character, give them a name and cursorybackstory, then kill them off at the end of the chapter, if not the end of the page. This is done mostly (but not only) to make the war feel real; Honor and other major characters can only be so many places at once (and are not likely to be on the losing sides of absolute massacres off in the boonies, but then again...), so giving a name to, say, the LAC pilot who will be killed shortly helps to make the reader realize the human implications.
This is invoked in Discworld, as it runs on the Theory of Narrative Causality. In Interesting Times, Ponder Stibbons notices that the magical supercomputer Hex is starting to think for itself, and reflects "We should never have named you. A thing with a name is a bit more than a thing".
Played with in the Ciaphas Cain (HERO OF THE IMPERIUM!) novels, which usually take care to name every member of every Redshirt Army Cain brings with him in the climax. Their survival rate appears to be somewhere in the lower thirties overall. Most people who die during the battle sequences do so unnamed, however, to say nothing of the mooks Cain, Jurgen and said Redshirt Army mow down by the dozens each book compared to the longer-lived named villains.
In Redshirts, Hester points out that he has neither an interesting background nor do his friends even bother to find out his first name, and is therefore just there to be a placeholder character.
The Star Wars Expanded Universe has an in-universe case with the Gand species, whose beliefs hold that you have to earn a name by accomplishing something that proves your importance.
Somewhat averted in the Millenium Trilogy. Many of the minor characters have names and descriptions, and even some background. At one point in the third book, Larsson devotes two pages to profiling a hospital orderly whose only role in the plot is that Blomkvist bribes him to smuggle in a cellphone for Salander.
Invoked in A Song of Ice and Fire. While arguing whether or not to sacrifice Edric Storm the pro-sacrifice side refers to him as "the boy" or "the bastard." Davos, who opposes the idea, resolves to use his name as frequently as possible.
Subverted in Stephen King's The Langoliers, where in the first chapter, protagonist Brian Engle meets a stewardess who introduces herserf as Melanie Trevor. At this point, a Genre Savvy reader starts foreshadowing a Romance Arc, but after just a couple of lines, the book explicitly states that Engle never saw Melanie Trevor again.
LARP: The Battle for Verona gives absolutely every character a name and short backstory, even if their only relevance is to say a single, unimportant line. It gets very distracting very quickly, as the few times the characters come up again, they get referred to once again by name, making the reader pause and try and remember who they are.
Live Action TV
The Fridge Brilliance section has a reference to the Doctor Who episode "Midnight" — where a monster controls people by forcibly repeating their dialogue and mentally turning them against one another. Nobody believes the Doctor when he tells them his usually fake name "John Smith". In the end the person who actually beats the villain of the week is the Hostess of the trip - and the cast realise, in the aftermath, that they never knew her name.
There're a handful of Doctor Who characters who actually have names but they're never mentioned in the story itself for various reasons (short screen time, situation means it never comes up, etc.). They're named in the credits though.
Burn Notice abuses this like crazy, though not the way you'd think. Most anyone with a line is given a name of some sort, generally because they're relevant to the plot of the episode. However, the show will occasionally bring back old characters as main characters.
Somewhat subverted in Veronica Mars in which almost all major and minor characters have first and last names that may be known by greater fans of the show. However, given that the large arcs of the show tended to included a large number of characters, this may not be surprising.
Played around with in the new Battlestar Galactica. Lots of one-shot characters without much importance have names, but (more importantly) several characters—most notably Diana Seelix—were promoted from near-extras to significant recurring characters simply because someone on the cast (usually Aaron Douglas) gave them names and the writers decided to Throw It In.
Played around with in Star Trek. Many unimportant characters, even the Red Shirts, are given names, while sometimes the Monster of the Week will kill unnamed ensigns and lieutenants throughout the ship or on the planet. Although, even when red shirts were given names, they were rarely given both first and last names.
In Star Trek: The Next Generation, Transporter Chief O'Brien O'Brien didn't even have a name or a job title the first season. He occasionally had a few lines of dialogue in the show's first three seasons, but was not a pivotal character in his own right. Early in Season 4 he is given a first name, Miles. Shortly after that he's given a Backstory, a wife (Keiko), some serious character development, and then is made a major character in Star Trek: Deep Space Nine.
Played with in House with "Thirteen", number 13 out of however many potential people were in the pool to take over the assistant jobs with house, and who continues to be called "Thirteen" for the entire run of the series except in very rare circumstances. Her real name is Remy Hadley. The first time she's actually addressed by her name (Cuddy calls her "Dr. Hadley"), everyone just looks around in confusion.
The Animal Planet series Too Cute follows various litters of kittens and puppies through the early stages of their lives. In the larger litters, only a couple are actually named and focused upon; the others' names simply aren't mentioned.
The section on creating NPC's references this, sparking a margin discussion between Dresden and Billy. Dresden comments that the random people do, in fact, have a name, to which Billy asks why Harry never writes them down in his case files. Dresden answers that he usually doesn't have time to ask, on account of many of them trying to kill him at the time.
In fact, the literal game term for minor non-player characters of not much importance is "nameless NPCs", thus hanging a nice lampshade on the trope. ("Supporting" and "main" NPCs, the other two big categories, get comparatively more comprehensive writeups and explicitly better plot armor.)
This is a common trope for theatre in general, where typically a character is only named if they're important to the plot, or if their name is spoken at some point.
This is averted in Urinetown the musical, where every single member character has a name, even though only 10 of the names are actually spoken (the rest are only written in the program).
Classically averted in the opera Tosca with the executioner Roberti. Not only is Roberti a very minor character (he appears in only two scenes), he doesn't sing, not even in chorus.
Largely averted in the Gilbert and Sullivan operas, in which every character gets a name (even some extremely minor ones, e.g. Fleta and Salata)—except for "First Yeoman", "Second Yeoman", "First Citizen", and "Second Citizen" in The Yeomen of the Guard. Also, the chorus never get names, because they have no solo work (though some directors change that).
In-universe, only the Elite- and Leader-Class Skrall are allowed to have names, whereas the Warrior class Skrall are nameless.
A real-world example: if a character gets named, it has to be an important player, considering clearing names through legal is a pretttty pricey deal. Which means every name that makes it through the process has to be put to good use.
Once the character has been used in the story, however, they may show up only to get killed for dramatic effect. An example of this is Botar, who first teleported in to arrest someone who had done Face-Heel Turn in the past. He later showed up for the same person's Heel-Face Turn in order to teleport a MacGuffin, but after that event Botar was only mentioned in passing as having been killed by one of the villains. Seeing as the series has been canceled as a toyline, and judging by the number of previously important characters that have died unceremoniously, fans began wondering what would happen to their beloved main characters once the list of new names ran out...
Lampshaded in Schlock Mercenary, where two grunts laugh about it, but are careful to give their names.
Lampshade Hanging in this, where the Genre Savvy Elan explains that not having a name means you're just a Red Shirt whose sole purpose is to say "I'll hold them off!" and then get killed. As if to demonstrate, two red shirts manage to survive a battle by revealing that they do have names, with one surviving a near-fatal injury by revealing his first name, and stating that he is saving his last name just in case he gets injured again. This particular Chekhov's Gun is later subverted. He attempts to invokeNominal Importance by shouting his last name, but only gets to "Daigo Da-" before being hit in the face with a door.
Subverted in this episode, where Belkar kills a random gnome for no particular reason (other than that he could). When his companions are horrified by this, he says the gnome was unimportant and "probably didn't even have a name"...even though the gnome had told the group his name 7 panels earlier.
He did it even earlier to the Chimera as it was cursing the Order. Haley even complained about Belkar killing it mid-speech, pointing out that since it had a name it was probably meant to be a recurring adversary.
Subverted several times in the prequel Start of Darkness: when Ekdysdioksosiirwo, Viridian Lord of— is killed because he gives his name, and the two main characters survive by giving shorter aliases, and when the named characters Aliyara, Ridiziak and Eriaxnikol, Right-eye's wife and sons are killed, and their unnamed daughter/sister survives. Also? The three main characters are called Right-Eye, Redcloak and Xykon. None of those are their real names.
Lampshaded (by Elan, naturally) in this strip. "Hooray! The people whose names I know are saved!"
The page image is taken from this strip, in which Hobgoblin Cleric #2 complains about Jirix being made Prime Minister of Gobbotopia. He could have got the job if his mother had given him a name less generic than 'Hobgoblin Cleric #2'.
Used during the "That Which Redeems" arc from Sluggy Freelance. Of the hundreds of Demonic Invaders, about a dozen are given names. Of these, only Bubbamonicus and Mospinispinosp are killed. Demons without names are torn apart like wet tissue paper.
Averted in RPG World. Galgarion fires one of his random guards, Evil Soldier #347, and he becomes a regular character set out to get revenge. His name remains Evil Soldier #347 throughout the entire comic.
Inverted with the Monarch's henchmen. #21 and #24 are recurring characters, while the two henchmen who receive names, Speedy and Scott Hall (Henchman #1), are killed in their first episode.
Played straighter later on, when we do eventually learn that 21's name is Gary. And 24 dies without us ever learning his
#21 and #24 even lampshade the fact that the series does not ascribe to this trope:
Henchman 24: Hey, here; what's your name? Henchman 1: Henchman number 1. Henchman 24: See, you are nameless. Henchman 1: I'm Scott Hall, my name is Scott Hall. Okay? Henchman 24: No, won't help. Henchman 21: Yeah, now it's just pathos. So you're dying in my lap and I'm all "Scott! Scott don't you quit on us! Don't you dare!!" Henchman 24: You just made your inevitable death more pathetic.
Ironically, it's revealed that Scott Hall did survive his Brock Samson beating, while 24, who mocked Scott's "inevitable" death, dies in the season 3 finale.
In Frisky Dingo the Xtacles were all Faceless Mooks that always wore their helmets, although a couple were named. In the first episode the Spin-OffXtacles a bunch of said soldiers take off their helmets and are given independent names. It's then partially subverted when a bunch of them die anyway.
The original Scooby-Doo series was famous for this to the point that the real person behind the Monster of the Week could easily be identified through the Scooby-Doo Rule: The first new character of the week to be introduced by full name was the guy in the rubber suit at the end. Later series are aware of this and try to muddle the rule's usefulness either by introducing too many characters at once to be able to pinpoint one in particular or by going Agatha Christie on the viewer and having everyone be in on the plot.
The Scallions from various episodes of VeggieTales lack names, other than their collective title of, well, "the Scallions". Lampshaded in one of the Silly Songs with Larry:
Larry: [Singing to the tune of "Funiculý, FuniculÓ"] ♪ Oh golly... ♫ [normal voice] Um... what's your name?
Scallion: They've never given me a name. [starts walking off screen] I've been around since show one, and I still don't have a name!