What stormtrooper designation does Finn have?

The story behind the answer

Finn is identified by Captain Phasma and First Order readouts with a designation ending in 2187; Poe then riffs on the “FN” prefix to give him a real name. The other options mimic First Order formats but don’t appear in canon. A common mix-up is with FN-2199 (“Nines”), the riot-baton trooper behind the “Traitor!” meme, not Finn. So if you remember Poe’s quip and the on-screen HUD, you can rule the near-miss numbers out.

The 2187 digits are a deliberate Easter egg: Princess Leia’s detention cell in A New Hope was 2187, itself paying homage to Arthur Lipsett’s experimental short “21-87,” a film that influenced George Lucas. By encoding that number into Finn’s ID, the sequels subtly link new characters to the franchise’s classic and cinematic roots.