"FAB," in the Thunderbirds television series, sounds like an acronym,
but it actually wasn't one (at least not as originally conceived by
the show's creator). It was more of an abbreviation. In the sixties,
"fab," which was short for "fabulous," was a very popular slang word,
particularly in the UK.
"International Rescue's London agent, international socialite Lady
Penelope Creighton-Ward, and her cockney butler/chauffeur Aloysius
'Nosey' Parker, are often seen chasing The Hood and other villains in
the pink, amphibious Rolls-Royce FAB 1, which is equipped with James
Bond-style gadgets. (Rolls-Royce actually provided an authentic
radiator grille to the production company for closeups of FAB 1 (such
as when the retractable machine gun was fired).) Lady Penelope's yacht
was called FAB 2.
The characters use the radio sign-off 'F.A.B.' rather than 'Roger' or
'Over and out'. Anderson was often asked what F.A.B. stood for, but in
fact it simply stood for 'fab' (short for 'fabulous'), a 1960s
catchphrase. Later this was unofficially decided to mean Fully Advised
and Briefed, following on from P-W-O-R (Proceeding With Orders
Received), a similar radio confirmation code in the series Stingray.
In Anderson's next series, Captain Scarlet and the Mysterons, S.I.G.
(Spectrum is Green) would continue the tradition of initialled call
"The Thunderbirds' radio code 'F-A-B', meaning 'message received and
understood', didn't stand for anything, it was just supposed to sound
'hip'. In fact, when asked what it stood for, Gerry Anderson once
replied, with some bemusement, 'Fab,' as though it were obvious.
Later, due in part to fan-submitted stories, F-A-B came to mean Fully
Advised and Briefed, in keeping with P-W-O-R (Proceeding With Orders
Received), a similar radio confirmation code in the series Stingray."
Internet Movie Database: Trivia for "Thunderbirds"
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