Unique and Universal

unique and universal – Universal personnel, ships, sites, missions, and time locations are those with the four-diamond ❖ universal symbol at the beginning of the card name. (Universal facilities will also be marked with the ❖ symbol in future printings.) Those without the ❖ universal symbol are unique (unless they have an Enigma icon ✶).  All other card types are universal unless marked “Unique” or “Not duplicatable.”
Each player may have only one copy of a particular unique (or Enigma)  personnel or ship (or of the same persona) or non-duplicatible facility in play at any time. Any number of copies of a universal personnel, ship, or facility may be in play at the same time. A player may not play a unique personnel, ship, or non-duplicatible facility if that player has a non-unique personnel, ship, or facility in play with the same title or persona (or vice- versa).
Unique sites are “unique per station.” That is, each Nor is limited to one of each kind of Site card. Universal sites may exist in multiple on each Nor.
Unique missions (including Q’s Planet) and time locations are not duplicatable. There may be only one copy of a time location in play at a time, for both players. Unique missions are stacked to create a single location. Each player may seed more than one copy of any universal mission.
Each player may have multiple copies of a facility, artifact, dilemma, objective, etc. in play at a time, except for cards marked “Unique” or “Not duplicatable” in their game text.
When any card marked “Unique” in its game text, or any unique or Enigma personnel or ship, is in play, another copy or instance of the same persona may not be played by the same player, and if another copy belonging to the same player is encountered (e.g., dilemmas), earned (e.g., artifacts), or activated (e.g., hidden agendas) by any player, that copy is discarded.
When any card marked “Not duplicatable” in its game text (or any unique time location) is in play, another copy may not be seeded or played by any player, and if another copy is encountered, earned, or activated by any player, that copy is discarded. When a player seeds any unique mission which has already been seeded on the spaceline, the second copy is stacked atop the first to create a single location. See Deep Space 9, seed phase