From the appendix:
" All artifacts appear on stations inventory within 3 days of game time.
Some artifacts such as the HSD, ENM, PAD and TMCD, all have indicators on the BridgeViewer. When these artifacts are in your cargo bay, they are green and when all conditions that deem them operable are met, they are light green.
Most artifacts require certain officers to be on station and have a certain AI level. Refer to the Crew section of this appendix.
Artifacts which are system upgrades can be immediately fitted when purchased without being subject to analysis by the RE.
Some artifacts cannot be installed on certain ship classes. So, if you purchase one and you can't install it, this means that the ship cannot support it. This is the same rule which applies to certain shield, armor, engine, reactor upgrades. Not all can be fitted on a ship. "
Where does it say that only one of each item can be installed at one time?
I'm only trying to learn about your game, just because it's obvious to you, you wrote the game, I'm asking questions about things that I haven't found covered in the manual or appendix or things that are not clear to me. I'm not trying to annoy you or anything, I just want some support and advise.