Delphi Ardu IV is the fourth planet of the Delphi Ardu system. The planet is classified as class M, and prior to 2364, had only been charted by the Federation via long-range scans, which indicated no lifeforms, sentient or otherwise.
It was the ancient site of an outpost of the extinct Tkon Empire, known as Outpost 63. (TNG: "The Last Outpost")