Top secret

Top secret is a term used to describe classified information, usually related to a government project, especially military or space launch missions.

The Cape Courageous space program was a top secret program, and only a person with a top-secret pass could enter the complex.

When Batman and Robin inquired about the owners of UltraTech to the UltraTech's secretary, she told them that's top secret. She likewise said the same thing in answer to their question about Marvin White and Wendy Harris visiting there.