The in-game description of the object is "keycard", and you can't do anything with the inventory item. The object is referenced in the scripts as "spcard". In the official release, the object graphic was removed, and is no longer present in the code, but the icon, Cursor 14, is present in both the beta and the released games code. One theory suggests that maybe it was something that you could get from the deceased policeman on Estros, and used to open the door to the Super Computer.