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
- Ark: Autobot Starship Ark, Autobot Ark (exceptional since it has never been used as a Transformers toy's name before)
- Blades: Autobot Blades, Blades the Copter-Bot (also used as part of prefixes for other characters' toys, such as "Battle Blades Optimus Prime" or "Night Blades Sideswipe")
- 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")
- Bludgeon: Decepticon Bludgeon (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)
- 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)
- Bruticus: Predacon Bruticus, Bruticus Maximus, Decepticon Bruticus
- Camshaft: Autobot Camshaft
- Cosmos: Autobot Cosmos
- Countdown: Autobot Countdown
- Devastator: Constructicon Devastator, Devastator Showdown, Destruction Site Devastator, Autobot Assault Devastator
- Drag Strip: Decepticon Drag Strip (only for the Universe "Special Edition" figure; the BotCon 2011 exclusive is simply named "Dragstrip", as one word)
- Drift: Autobot Drift (exceptional since it has never been used as a Transformers toy's name before)
- Dropshot: Decepticon Dropshot
- Flamewar: Decepticon Flamewar
- Fracture: Decepticon Fracture (exceptional since it has never been used as a Transformers toy's name before)
- Frenzy: Decepticon Frenzy
- 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
- Guzzle: Autobot Guzzle
- Hatchet: Decepticon Hatchet (exceptional, since the name was never used on a Transformer before)
- Heavy Load: Decepticon Heavy Load
- 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 packaging, including the bio, consistently refers to him as "Protectobot Hot Spot", while the instructions identify him as "Hotspot™")
- Hound: Autobot Hound, Tracker Hound
- Jazz: Autobot Jazz, Final Battle Jazz, Protoform Jazz, Battle Jazz, Freeway Jazz, Stealth Ninja Jazz (only released in Australia), Special Ops Jazz
- Kup: Sergeant Kup
- Nautilator: Decepticon Nautilator
- Piranacon: Decepticon Piranacon
- 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)
- 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)
- Rumble: Decepticon Rumble, Demolition Rumble (the latter currently still 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")
- Roadbuster: Autobot Roadbuster, Track Battle Roadbuster
- Roller: Autobot Roller (exceptional since it was never used as a toy trademark before)
- Scrapper: Decepticon Scrapper (Classics Constructicon Devastator giftset only; the Revenge of the Fallen toys are simply named "Scrapper")
- Seawing: Decepticon Seawing
- Skids: Autobot Skids, Missile Blast Skids, Offroad Skids, Tuner Skids
- Slicer: Decepticon Slice (only on his bio card; the polybag packaging calls him "Slicer")
- Snaptrap: Decepticon Snap Trap (the name itself also parsed as two words)
- Springer: Autobot Springer (but simply "Springer" for the Voyager Class figure in the Target-exclusive 2008 Universe two-pack)
- Tailgate: Autobot Tailgate
- Tarantulas: Predacon Tarantulus (using the spelling "Tarantulus" only once), Predacon Tarantulas
- Tentakil: Decepticon Tentakil
- Topspin: Autobot Topspin, Autobot Armor Topspin
- Tracks: Autobot Tracks, Turbo Tracks
- Whirl: Autobot Whirl
- Wheelie: Autobot Wheelie (but simply "Wheelie" for the Asian market exclusive Generations Deluxe Class figure)
Prefixes NOT needed for trademark reasons
- 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.
- 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.
- 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".
- 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
- 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
- Kup: Autobot Kup
- 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")
- 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:

