F91 may refer to :
*
F91 Dudelange, a football club, based in Dudelange in southern Luxembourg
* ''
Mobile Suit Gundam F91
is a 1991 anime film. It was ''Gundam'' creator Yoshiyuki Tomino's attempt to launch a new ''Gundam'' saga, set 30 years after ''Char's Counterattack''. He re-teamed with character designer Yoshikazu Yasuhiko and mecha designer Kunio Okawara for ...
'', a 1991 animated film
*
HMS Brazen (F91)
HMS ''Brazen'' was a Type 22 frigate of the Royal Navy. She was completed three months ahead of schedule due to the Falklands War.
Royal Navy service
''Brazen'' served on the Armilla Patrol which became a task force during the Gulf War as par ...
, a 1981 British Royal Navy Type 22 frigate
*
HMS Murray (F91), a British Royal Navy Blackwood class second-rate anti-submarine frigate
* Republic
XF-91 Thunderceptor, a rocket-jet hybrid interceptor
*
Casio F-91W, a common and inexpensive digital watch, claimed by some to be associated with
terrorism
* The
McCarthy 91 function
The McCarthy 91 function is a recursive function, defined by the computer scientist John McCarthy as a test case for formal verification within computer science.
The McCarthy 91 function is defined as
:M(n)=\begin
n - 10, & \mboxn > 100\mbox ...
, a recursively defined mathematical function
and also:
*
Conduct disorders
Conduct disorder (CD) is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior that includes theft, lies, physical violence that may lead to destruction, and reckles ...
ICD-10 code
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