There's almost no such thing as a person having an occupation - be they mundane, fantastic, heroic, or villainous - without some form of recognizable implement that's important and often necessary for them to serve their role, and as such these items tend to be handy in readily identifying them. The Signature Device is a tool, weapon, or object that all members of a certain group (usually Differently Powered Individuals) possess. Sometimes it's a Transformation Trinket; sometimes it's an iconic tool of their profession.
Naturally, if an organization or faction uses these as means of identification, they tend to consider it a vendetta-worthy offense for an outsider to be seen with one. Even if it was not pried out of the cold dead fingers of a legitimate owner.
- The Air Trecks in Air Gear.
- The Beyblades from Beyblade
- Zanpakouto in Bleach. (Dolls for the Filler Arc's Bounts.)
- Knightmare Frames from Code Geass.
- Digivices for the Digidestined from Digimon
- Diaries (of all sorts) in Future Diary.
- The eponymous Gundams
- Controllers in Hunter X Hunter each have one.
- The Vongola (Mare/Acrobaleno Pacifiers) Rings from Katekyo Hitman Reborn.
- The Guns from Letter Bee that the Letter Bees all use.
- Pokeballs and the Pokedex from Pokémon
- Tennis rackets in Prince of Tennis
- The transformation wands from Sailor Moon.
- Yu-Gi-Oh!: Duel Disks in all their shapes and forms.
- The Books from Zatch Bell
- Star Wars: Lightsabers, for Jedi; Sith Lords use them too, usually with red blades.
- By later James Bond films, the Walther PPK becomes one for Bond even in universe, as noted by GoldenEye. A large part of this is that it is over half a century out of date (Bond being the only reason it's produced anymore) and in a low power caliber that never took off outside of western Europe. It never reached this status in the original books since by Ian Fleming's death they were still floating around as untraceable surplus from World War II and easily obtained by any spy agency in the world.
Walther PPK, 7.65 millimetre. Only three men I know use such a gun... and I believe I've killed two of them.
- The Neuralyzer, for the eponymous Men in Black from the MIB films.
- The Three Musketeers all use rapiers. Not muskets, ironically. And in most adaptations, Nice Hats with plumes.
- In the Dresden Files, the silver, anti-magic sword and unstainable grey cloak of the Wardens is this.
- Played with - focii help focus a wizard's magic in large part because they believe it will. However, there are also items imbued with power. Harry's are the staff and wand and duster (and gun).
- Wizards robes are both a symbol of office and needed because magic interferes with electronics, including heaters.
- In the Sword of Truth books it's the ... Sword of Truth. For the Seeker of Truth.
- At the palace of the prophets, the Rada'Han is this for wizards.
- Confessors' dresses.
- Higher-rank wizards wear simpler clothes.
- Defenders of the Lord Rahl wear special weapons with his crest.
- War Wizards' gear is this.
- The rings in the lips of the female slaves of the Imperial Order.
- Darken Rahl's curved knife.
- The Mord-Sith Agiel. Various colors of leather outfits, too.
- Morphers for the titular Power Rangers
- The Swords that the Shadow Chasers use.
- The sonic screwdriver and TARDIS of Doctor Who and the Time Lords
- The transporter has appeared in every incarnation of Star Trek.
- "Garage Door Openers" for all Stargate team members.
- Transformation Trinket belts for Kamen Riders.
- Dungeons and Dragons settings often use such trinkets - some magical, some not.
- Holy symbols. They almost never are exclusive for clergy - sometimes lay worshipers wear them as a sign of devotion - but practically anyone wearing what you recognize as a holy symbol of some deity almost certainly either is a priest thereof or at least belongs to the church hierarchy.
- Drow nobles get House Insignia - an amulet with their heraldic device and some magical powers, mostly of utility sort. Typically they double as magical "keys" for most security magic on their estate(s), obedience enchantments on mounts, and so on - and are booby-trapped, so that an outsider who took one from the rightful owner's body faces a nasty curse rather than freebies.
- Forgotten Realms has enchanted pins used by Harpers. Cormyr has common enchanted items for army (Purple Dragon's ring, Commander's ring) and War Wizards (War Wizard's cloak) that double as a "badge" of office and "pass card", in that they are compatible keys to certain generic wards (such as barracks and armories) enforcing different levels of security clearance. Witches of Rashemen have their enchanted masks - though there's a wide variety of those, they have a common recognizable look.
- Al-Qadim got amulets of sorcerous societies. Again, those are both used as identification marks and have magic keyed on them, starting from the spell broadcasting a message (used mostly as a request for help) to all bearers of the amulet in range.
- Deathwatch has items specific for a Chapter of Space Marines, including "Chapter Trappings" — mostly heraldry, mementos or miscellaneous gear granting minor bonuses (e.g. Raven Guard may carry Helmet Picter to review footage after the mission and possibly grant all participants extra XP), though also including ceremonial-yet-functional weapons, like Ceremonial Sword of the Dark Angels or Sacris Claymore of the Storm Wardens.
- Most stock costumes, which are themselves generally examples of Truth in Television. Particularly:
- Scrubs, stethoscopes and clipboards for doctors
- Guns and badges for police officers
- Cellphones, PDAs or Bluetooth headsets for businessmen
- The beak-like leather masks (filled with "protective" aromatic/medicinal herbs) worn by medieval doctors during periods of plague.
- The "square and compass" symbol of the Freemasons is made up of two signature tools of stonemasons.
- Daishō, matched pair of long and short blades (mostly katana plus wakizashi, but any sword plus tantō fits too) were signature weapons of the samurai. After "sword hunt" and for more than two centuries this was legally formalized and enforceable as both privilege and duty.