INCO was an agency or title held by a Starfleet officer at Starfleet Command's Fleet Operations Center, Sol Sector.
In January of 2155, Starfleet officers V. Deadrick, Jr. and D. Lehrhoff was working in or as INCO. It and the officers' name were listed on directory placards. (ENT: "Demons", directories)
INCO, like many of the other agencies or titles on the directories, was a reference to NASA and ISS terminology, in this case, the "Instrumentation and Communications Officer".