Starfleet Intelligence was the intelligence branch of Starfleet, reported to the Chief of Starfleet Strategic Operations, with a mission to gather data pertaining to military, industrial and diplomatic entities in the galaxy.
It was headquartered on Earth, among the many buildings of Starfleet Command in San Fransico.
It would share information and perform joint operations with the Federation Intelligence Service.
In 2371 Kaylon was serving as a liaison officer from the Vulcan Security Service.
Vice Admiral Fujisaki was replaced as Director of Starfleet Intelligence after dying of food poisoning in 2374.
It had undercover officers serving throughout Starfleet, placing them at high-risk installations, starbase, and starships, often without the commander's knowledge.
During the USS Vander's two-year deep space mission, T'naal was placed on board as Chief Navigation Officer. ("Space-jacking Prefix")