And SCIF's are for discussing TSCI stuff.
TSCI is Top Secret Compartmentalized Information.
The key word here is compartmentalization. You break a Top Secret program into multiple different "pieces"… like one group handles the ELINT (electronic intelligence), the other HUMINT (human intelligence), and still others SIGINT (signals intelligence). And each of those departments can be further compartmentalized.
Now, each person working in each compartmented group will HAVE NO ACCESS to the other groups work plans and likely will have no clue who else is in the other working groups.
What you dont know wont hurt you.
Breaking any TSCI and SCIF rules is a GUARANTEE of your ass sitting in a one way windowed room answering questions hoping you will see the light of day again.