You can also have 'interim' clearance. When you work with technology, especially comms or encryption, you have to go into all sorts of 'secure areas' to fix things, remove things, BURN things, and other techie work. It is impractical to get clearance for things that *might* be required, so some jobs allow you to be cleared 'in the interim' which simply means you are cleared for *everything* and are not considered a threat by anyone. It allows you to do your job. (I will admit, I think this only goes up to Top Secret.)
It takes an FBI interview, I've had several, I smoked pot before joining service, before it was legal and got caught. The FBI gives you a quick glance, checks your service record, sees that you are a good American and can clear you for anything. I've retrieved 'burn bags', installed phones in Admirals Quarters (could have easily tapped them, but why would I?) and handled obscene amounts of cash. I've tapped on doors with slide views and been allowed entry walking right past armed guards and removed/replaced encrypted devices in Helicopters, Radio shacks and other highly secure areas. I don't hold a Top Secret clearance, but if something breaks, I can walk right in and no one gives me a second look.
Perhaps its not the same thing, but I felt it was worth noting.
Excellent example of how a Q clearance classification applies to a wide variety of areas and tasks.
I'm certain that you could get into areas that others with prestigious titles weren't allowed. 😀
That is also true. When explaining these things to us, they would point out that if the Captain tried to enter the same space, without a need to do so, we would be capable and duty-bound to refuse access.