In Explained

IN, In or in may refer to:

Places

India (country code IN)
Indiana, United States (postal code IN)
Ingolstadt, Germany (license plate code IN)
In, Russia, a town in the Jewish Autonomous Oblast

Businesses and organizations

Independent Network, a UK-based political association
Indiana Northeastern Railroad (Association of American Railroads reporting mark)
Indian Navy, a part of the India military
Infantry, the branch of a military force that fights on foot
IN Groupe, the producer of French official documents
MAT Macedonian Airlines (IATA designator IN)
Nam Air (IATA designator IN)

Science and technology

.in, the internet top-level domain of India
Inch (in), a unit of length
Indium, symbol In, a chemical element
Intelligent Network, a telecommunication network standard
Intra-nasal (insufflation), a method of administrating some medications and vaccines
Integrase, a retroviral enzyme

Other uses

In (album), by the Outsiders, 1967
In (Korean name), a family name and an element in given names
"In", an episode of Minder
Imperishable Night, the eighth official game in the Japanese Touhou series
Indonesian language (former ISO 639-1 language code; "id" used since November 3, 1989)
In Nomine, a title given to any of numerous short pieces of English polyphonic instrumental or vocal music during the 16th and 17th centuries

See also