Definition of "IOC"

(business) Initialism of interoffice communication.  examples

(military) Initialism of initial operating capability.

(computer security) Initialism of indicator of compromise.  examples

Initialism of Italian organized crime.  examples

Initialism of international oil company.  examples

(finance, of an order) Initialism of immediate or cancel.  examples

(sports) Initialism of International Olympic Committee.  examples

(ornithology) Initialism of International Ornithological Committee. (now known as International Ornithologists' Union)