IFF

(in Airplanes) electronic device that transmits a 4-digit identification code to the scanning surface radar in order to identify itself as "friendly" aircraft

IFF, Iff or iff can stand for:if and only if, a mathematical and logical connector indicating that either both statements are true or both are falseIdentification friend or foe, an electronic radio based identification system utilizing transpondersIn Flanders Fields Museum, a World War I museum located in Ypres, BelgiumInterchange File Format, a computer file format introduced in 1985 and later extended into many othersInternational Fashion FederationInternational Floorball Federation, the global governing body for the sport of floorballInternational Flavors and Fragrances, a company producing flavors and fragrancesInternational Freedom FoundationInternational Film FestivalInternational Finance FacilityIntroduction to Fighter Fundamentals, a U.S. Air Force formal training course for new fighter pilotsIslamic Republic of Iran Football Federation, the Iran Football FederationInternational Freedom Fighters, an American Army gaming clan
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↔⇔≡logical symbolsrepresenting iff. If and only if, in  logic and fields that rely on it such as mathematics and philosophy, is a logical connective between statements which means that the truth of either one of the statements requires the truth of the other. Thus, either both statements are true, or both are false.
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Abbreviation for identification, friend or foe.

A system using electromagnetic transmissions to which equipment carried by friendly forces automatically responds, for example, by emitting pulses, thereby distinguishing themselves from enemy forces. [JP1] Note: The secondary surveillance radar (SSR) system used in modern air traffic control systems is an outgrowth of the military IFF system used during World War II. The IFF equipment carried by modern military aircraft is compatible with the transponder system used for civilian air traffic control.

1. <file format> Interchange File Format.
2. Identify friend or foe (radar).

<mathematics, logic> if and only if, i.e. necessary and sufficient. For example, two figures are congruent iff one can be placed over the other so that they coincide.
(2002-12-28)

If and only If