Trademark/Altered names
In order to retain trademark on character names, sometimes Hasbro and Takara will strengthen their claim by adding prefixes or suffixes to a character name.
Hasbro
- Anvil: Decepticon Anvil (exceptional since it has never been used as a Transformers toy's name before)
- Apex: Autobot Apex
- Ark: Autobot Starship Ark, Autobot Ark (exceptional since it has never been used as a Transformers toy's name before)
- Back: Decepticon Back (exceptional since it has never been used as a Transformers toy's name before)
- Berserker: Decepticon Berserker (exceptional since it has never been used as a Transformers toy's name before)
- Blackjack: Decepticon Blackjack
- Blades: Autobot Blades, Blades the Copter-Bot, Blades the Flight-Bot, Protectobot Blades (also used as part of prefixes for other characters' toys, such as "Battle Blades Optimus Prime" or "Night Blades Sideswipe")
- Blast Off: Decepticon Blast Off
- Blaster: Autobot Blaster (also used as part of names of weapons that aren't related to an actual "Blaster" character, such as "Requiem Blaster", "Energon Blaster" or "Umbral Blaster")
- Blot: Terrorcon Blot
- Bludgeon: Decepticon Bludgeon (2001 Robots in Disguise Bludgeon was officially named "Destructicon Bludgeon", with an individual ™ claim after each word, which at least technically means that Hasbro still claimed "Bludgeon" as a trademark by itself in 2003)
- Boulder: Boulder the Construction-Bot (exceptional since it has never been used as a Transformers toy's name before)
- Brawl: Decepticon Brawl, Deep Desert Brawl, Desert Blast Brawl (also used as part of multi-pack names such as "Freeway Brawl", "Back Road Brawl", "Desert Ruins Brawl" and "Streetside Bot Brawl", of which only the third actually includes a "Brawl" character); but now back to simply "Brawl" without prefix again as of 2015
- Bruticus: Predacon Bruticus, Bruticus Maximus, Decepticon Bruticus; but now back to simply "Bruticus" without prefix again as of 2015
- Camshaft: Autobot Camshaft
- Chase: Autobot Chase (only for the instructions of early Titans Return Roadburn samples), Chase the Dino Protector, Chase the Police-Bot,
- Chop Shop: Decepticon Chop Shop (only two years after the release of a toy simply named "Chop Shop"!)
- Cosmos: Autobot Cosmos
- Countdown: Autobot Countdown
- Cutthroat : Terrorcon Cutthroat
- Devastator: Constructicon Devastator, Devastator Showdown, Destruction Site Devastator, Autobot Assault Devastator; but now back to simply "Devastator" without prefix again as of 2015
- Doubledealer: Decepticon Doubledealer
- Drag Strip: Decepticon Drag Strip, Decepticon Dragstrip (the BotCon 2011 exclusive, released between these two uses, was simply named "Dragstrip", as one word)
- Dragonus: Autobot Dragonus, Decepticon Dragonus, Mini-Con Dragonus (exceptional since it has never been used as a Transformers toy's name before)
- Drift: Autobot Drift (exceptional since it has never been used as a Transformers toy's name before)
- Dropshot: Decepticon Dropshot
- Eclipse: Autobot Eclipse (exceptional since it has never been used as a Transformers toy's name before)
- Fangry: Decepticon Fangry
- First Aid: Protectobot First Aid
- Flamewar: Decepticon Flamewar (only for the Transformers Prime character; oddly, both the BotCon 2005 exclusive figure, which introduced the name, and the BotCon 2014 exclusive are both simply named "Flamewar™")
- Forth: Decepticon Forth (exceptional since it has never been used as a Transformers toy's name before)
- Fracture: Decepticon Fracture (exceptional since it has never been used as a Transformers toy's name before)
- Frenzy: Decepticon Frenzy
- Full-Tilt: Decepticon Full-Tilt
- Gears: Autobot Gears
- Grapple: Autobot Grapple (misspelled as "Auotbot Grapple" in several instances on the Commemorative Series reissue's packaging; also used as part of "Grapple Grip Mudflap", which isn't a "Grapple" character; spelled "Grappel Grip Mudflap" on the European packaging), Solar Storm Grappel (see notable/unusual cases for more)
- Groove: Autobot Groove, Protectobot Groove
- Groundbuster: Decepticon Groundbuster (only two years after the release of a toy simply named "Groundbuster"!)
- Guzzle: Autobot Guzzle
- Hammer: Decepticon Hammer
- Hatchet: Decepticon Hatchet (exceptional since it has never been used as a Transformers toy's name before)
- Hazard: Decepticon Hazard (exceptional since it has never been used as a Transformers toy's name before)
- Headstrong: Predacon Headstrong
- Heatwave: Heatwave the Fire-Bot, Autobot Heatwave
- Heavy Load: Decepticon Heavy Load
- Hoist: Hoist the Tow-Bot (only for the Rescue Bots character; all other Transformers toys named "Hoist" sport no prefix)
- Hook: Decepticon Hook, Constructicon Hook
- Hot Rod: Autobot Hot Rod
- Hot Spot: Autobot Hot Zone (the ultimate real "Autobot Carblast" case - renaming "Hot Spot" into "Hot Zone" and adding an "Autobot" prefix) used only once, the Titanium Series figure is simply named "Hot Zone", without prefix; Protectobot Hot Spot (oddly, the Generations "GDO" figure's packaging, including the bio, consistently refers to him as "Protectobot Hot Spot", while the instructions identify him as "Hotspot™"; later figures consistently use the "Protectobot" prefix)
- Hound: Autobot Hound, Tracker Hound
- Hun-Gurrr: Terrorcon Hun-Gurrr
- Infinitus: Autobot Infinitus (exceptional since it has never been used as a Transformers toy's name before)
- Jazz: Autobot Jazz, Final Battle Jazz, Protoform Jazz, Battle Jazz, Freeway Jazz, Stealth Ninja Jazz (only released in Australia), Special Ops Jazz, Smooth Jazz
- Krok: Decepticon Krok
- Kup: Autobot Kup, Sergeant Kup
- Medix: Medix the Doc-Bot (only for the Rescue Bots character; the BotCon 2016 customization class figure was simply named "Medix")
- Moonracer: Autobot Moonracer (exceptional since it has never been used as a Transformers toy's name before)
- Murk: Decepticon Murk (exceptional since it has never been used as a Transformers toy's name before)
- Nautica: Autobot Nautica (exceptional since it has never been used as a Transformers toy's name before)
- Nautilator: Decepticon Nautilator
- Necro: Decepticon Necro (exceptional since it has never been used as a Transformers toy's name before)
- Nitro Zeus: Decepticon Nitro (exceptional since it has never been used as a Transformers toy's name before)
- Novastar: Autobot Novastar (exceptional since it has never been used as a Transformers toy's name before)
- Octane: Decepticon Octone
- Offroad: Decepticon Offroad (exceptional since it has never been used as a Transformers toy's name before)
- Overlord: Decepticon Overlord
- Outback: Autobot Outback
- Pipes: Autobot Pipes
- Piranacon: Decepticon Piranacon
- Pounce: Decepticon Pounce
- Powerglide: Autobot Powerglide
- Primus: Cybertron Primus (exceptional since it has never been used as a Transformers toy's name before; also used as part of the "Primus Unleashed" subline imprint's name)
- Ptero: Autobot Ptero (exceptional since it has never been used as a Transformers toy's name before)
- Quake: Decepticon Quake
- Rampage: Predacon Rampage
- Ratchet: Autobot Ratchet, Rescue Ratchet, Rescue Torch Ratchet, Desert Tracker Ratchet, Night Ops Ratchet, Specialist Ratchet
- Ravage: Battle Ravage, Command Ravage (both abandoned, back to simply "Ravage" since 2007)
- Revolver: Decepticon Revolver (exceptional since it has never been used as a Transformers toy's name before)
- Rewind: Autobot Rewind
- Rippersnapper: Predacon Rippersnapper, Terrorcon Rippersnapper
- Roadbuster: Autobot Roadbuster, Track Battle Roadbuster
- Roller: Autobot Roller (exceptional since it was never used as a toy trademark before)
- Rook: Protectobot Rook
- Rumble: Decepticon Rumble, Demolition Rumble (the latter unreleased; "Rumble" was also used as part of multi-pack names such as "Rotorwash Rumble" or "Hunters Rumble" that don't actually include a "Rumble" character, and as part of a prefix for Activators redecos, "Rally Rumble Bumblebee" and "Rally Rumble Optimus Prime")
- Scoop: Autobot Scoop
- Scrapheap: Junkion Scrapheap
- Scrapper: Decepticon Scrapper (Classics Constructicon Devastator giftset only; all subsequent toys (except the Combiner Wars Devastator giftset) are simply named "Scrapper"), Constructicon Scrapper
- Seawing: Decepticon Seawing
- Shockwave: Decepticon Shockwave (following several years of toys simply named "Shockwave"!)
- Shuffler: Autobot Shuffler (exceptional since it has never been used as a Transformers toy's name in Hasbro's markets before)
- Sixshot: Six Shot
- Skids: Autobot Skids, Missile Blast Skids, Offroad Skids, Tuner Skids
- Slash: Dinobot Slash (exceptional since it has never been used as a Transformers toy's name before)
- Slicer: Decepticon Slice (only on his bio card; the polybag packaging calls him "Slicer")
- Sludge: Dinobot Sludge
- Slug: Dinobot Slug (exceptional since it has never been used as a Transformers toy's name before)
- Snaptrap: Decepticon Snap Trap (the name itself also parsed as two words)
- Sovereign: Autobot Sovereign (exceptional since it has never been used as a Transformers toy's name before)
- Springer: Autobot Springer (but simply "Springer" for the Voyager Class figure in the Target-exclusive 2008 Universe two-pack)
- Sqweeks: Autobot Sqweeks (exceptional since it has never been used as a Transformers toy's name before)
- Stinger: Decepticon Stinger (exceptional since it has never been used as a Transformers toy's name before)
- Streetwise: Protectobot Streetwise
- Stripes: Autobot Stripes (exceptional since it has never been used as a Transformers toy's name in Hasbro's markets before)
- Stylor: Autobot Stylor
- Sweep: Decepticon Sweep
- Swoop: Dinobot Swoop
- Tailgate: Autobot Tailgate
- Tarantulas: Predacon Tarantulus (using the spelling "Tarantulus" only once), Predacon Tarantulas
- Tentakil: Decepticon Tentakil
- Teslor: Autobot Teslor (exceptional since it has never been used as a Transformers toy's name before)
- Thrash: Infernocon Thrash (exceptional since it has never been used as a Transformers toy's name before)
- Topspin: Autobot Topspin, Autobot Armor Topspin
- Tracks: Autobot Tracks, Turbo Tracks
- Twincast: Twin Cast (exceptional since it has never been used as a Transformers toy's name in Hasbro's markets before)
- Twinferno: Autobot Twinferno (exceptional since it has never been used as a Transformers toy's name before)
- Viper: Decepticon Viper (exceptional since it has never been used as a Transformers toy's name before)
- Vortex: Decepticon Vortex
- Whirl: Autobot Whirl
- Wheelie: Autobot Wheelie (but simply "Wheelie" for the Generations "GDO" Deluxe Class figure)
Unusual one-off prefixes not required for concurrent/subsequent toys
- All of the Combiner Wars Constructicons from the Devastator giftset have a "Constructicon" prefix even though only Hook would need one. This was likely done for consistency across the team.
- Bombshell: "Insecticon Bombshell" only for the Generations Platinum Edition reissue; the concurrently released Generations Combiner Wars Legends Class figure was simply named "Bombshell" without a prefix.
- Firestrike: "Autobot Firestrike" only for the Bot Shots figure; the Kre-O Kreon was simply named "Firestrike", and Hasbro also used the name without a prefix for their Nerf line.
- Flak: "Autobot Flak" only for the 2010 Transformers toy. Both BotCon 2009 Flak (released a year earlier) and Dark of the Moon Cyberverse Flak (released a year later) were simply named "Flak" without a prefix.
- Grimlock: "Dinobot Grimlock" only for the Power of the Primes Voyager Class toy, likely for consistency with the rest of the Dinobots. It should be noted that each word has an individual ® claim ("Dinobot® Grimlock®") rather than the name being one compound trademark.
- Leadfoot: "Classic Leadfoot" only for the Dark of the Moon rerelease of his Speed Stars toy, presumably to distinguish him from the Dark of the Moon Wrecker of the same name.
- Optimus Prime: "Autobot Optimus Prime" for a single release of the Movie Voyager Class toy with "battle damage" deco that was only available in Asia and from US-based online retailers. In this case, the "Autobot" prefix was probably only intended to distinguish this release from all the numerous other "Optimus Prime" toys from the Movie line.
- Reverb: "Decepticon Reverb" only for the unreleased Target exclusive Movie Scout (intended to be released in 2008). Cybertron Reverb (who had his last toy released in 2006, as part of the Shadow Recon Mini-Con Team), Revenge of the Fallen Reverb (2009) and Dark of the Moon Human Alliance Reverb (2011) were all simply named "Reverb", without a prefix.
- Sideways: "Decepticon Sideways" for a Toys"R"Us exclusive Revenge of the Fallen two-pack with Wheelie that was released in Europe. Presumably, this was simply because "Decepticon Sideways" sounds better together with "Autobot Wheelie" than a mere "Sideways" without the prefix.
- Sinnertwin: "Terrorcon Sinnertwin" for the instructions of Power of the Primes toys, but Sinnertwin's packaging and card render his name with no prefix.
- Strafe: "Dinobot Strafe" for some Age of Extinction toys; the majority of them, however, are simply named "Strafe" without a prefix.
- Wheeljack: "Autobot Wheeljack" for the KB Toys exclusive "G1" Spychanger... but only on the cardbacks of the entire Spychanger lineup. On the front side of his own card, he was simply named "Wheeljack", without a prefix. Since then, multiple "Wheeljack" toys have been released without a prefix.
- All other prefixes used for same-character redecos of toys that didn't require a prefix for their original release.
Cosmetic prefixes that don't actually allow Hasbro to use a trademark
- Erector was referred to as "Autobot Erector" for his 2011 Hall of Fame nomination bio. As the word "Erector" in the domain of toys is thoroughly trademarked by Meccano Ltd for Erector Set construction toys (they even own it specifically for toy robots!), this was something of an empty gesture, as putting "Autobot" in front of his name wouldn't actually allow Hasbro to use that trademark in the field of toys. (Granted, a write-up on a webpage isn't actually something that you can trademark...)
TakaraTomy
Japanese trademark law has apparently changed in recent years, in a way very similar to American trademark law. As a consequence, TakaraTomy also started using prefixes with one of the last Transformers Collection reissues, followed by several more cases in Henkei!.
TakaraTomy's versions of the Movie, Revenge and Darkside Moon toy lines used the same names as their Hasbro counterparts for the most part, including "Autobot" and "Decepticon" prefixes for a lot of names (though Skids, Springer and Devastator didn't require "Autobot" or "Constructicon" prefixes). However, TakaraTomy also added more prefixes for toys whose Hasbro versions didn't have prefixes (or, in one case, for giving a redeco a Generation 1-based Hasbro name that is unavailable to Hasbro altogether). This usually only applies to listings of these toys by online stores and in Japanese hobby magazines in katakana. For toys with Hasbro counterparts, the English names on the packaging were unchanged from the Hasbro versions.
With Transformers Animated and Transformers United, TakaraTomy once again mostly followed Hasbro's naming choices (although Animated Bulkhead and Ironhide were renamed into "Ironhide" and "Armorhide", respectively, and the United version of Straxus was released under that name rather than Hasbro's substitute name "Darkmount"). Once again, some names featured more prefixes that either were not required by or differed from their Hasbro counterparts. On the toys' packaging, the names were spelled with those prefixes both in English and in katakana.
- Barricade: Decepticon Barricade, Interrogator Barricade, Barricade & Frenzy
- Blazemaster: Autobot Blazemaster
- Blurr: Autobot Blurr
- Booster X10: Decepticon Booster X10
- Brakedown: N.E.S.T. Scout Brakedown
- Brawl: Decepticon Brawl, Electronic Brawl (only toys from the 2007 Movie line; the Encore reissue of the Generation 1 toy and the 2010 EZ Collection toy of the movie character were simply named "Brawl")
- Breakaway: Autobot Breakaway
- Breakdown (same katakana spelling as "Brakedown"): War Breakdown, Silas Breakdown, Zombie War Breakdown
- Cheetus: Cybertron Cheetus
- Firebolt: Autobot Firebolt
- Grapple: Autobot Grapple
- Hook: Decepticon Hook
- Hot Rod: Cybertron Hot Rod
- Inferno: Cybertron Inferno
- Jazz: Autobot Jazz
- Knock Out: Autobot Knock Out, Medic Knock Out, Bloody Knock Out
- Kup: Autobot Kup
- Laserwave: Destron Laserwave
- Lockdown: Decepticon Lockdown, N.E.S.T. Lockdown
- Longarm: Autobot Longarm
- Lugnut: Decepticon Lugnut
- Mixmaster: Decepticon Mixmaster
- Octone: Destron Octone
- Overload: Decepticon Overload
- Perceptor: Cybertron Perceptor, Autobot Perceptor
- Power Up VT6: Decepticon Power Up VT6
- Rampage: Decepticon Rampage
- Ratchet: Autobot Ratchet, Desert Tracker Ratchet, N.E.S.T. Autobot Ratchet (only toys from the 2007 Movie and Revenge lines; Henkei Ratchet, Animated Ratchet and Darkside Moon toys are simply named "Ratchet")
- Runabout: Decepticon Runabout
- Runamuck: Decepticon Runamuck
- Scourge: Decepticon Scourge
- Sentinel: Autobot Sentinel (exceptional as he's missing his Hasbro counterpart's "Prime" suffix)
- Shockwave: Decepticon Shockwave (only the Animated toy; the Darkside Moon toy is simply named "Shockwave")
- Sling: Cybertron Sling
- Streak: Cybertron Streak
- Sunstorm: Decepticon Sunstorm
- Swerve: Autobot Swerve
- Swoop: Autobot Swoop
- Thunderwing: Decepticon Thunderwing
- Tracks: Autobot Tracks
- Vorter: Destron Vorter
- Vortex: Decepticon Vortex
- Wheelie: Autobot Wheelie (only the Revenge character; Henkei Wheelie is simply named "Wheelie")
- Wildrider: Stuntron Wildrider, Stunt Wildrider (previously announced as "Stunticon Wildrider")
- Wipe-Out: Decepticon Wipe Out
For the Device Label line, which falls into a different product category than "toys", TakaraTomy also needed prefixes for some names:

