A file directory was a list of files present on a computer system.
At some point during or after being brought to the Delta Quadrant, the missile Dreadnought sustained damage causing some files in its file directory to be missing. As a result, it mistakenly set out to attack Rakosa V. (VOY: "Dreadnought")
Around 2372, the Klingon High Council instituted a security procedure in which the apparent main file directory on their ships contained false directories, files, and entire databases of disinformation designed for spies to steal. (DS9: "Sons of Mogh")