Please explain the pkg_check F option, thank you.

What exactly does the pkg_check -F option? If I use it, it does some filesystem check, and some "Locating unknown files".

At the end I get: "Locating unknown files: ok", "Locating unknown directories: ok", and a long list of "not found" directories and files, like below.
Not found:
/boot
/bsd
/bsd.rd
/bsd.sp
/bsd.syspatch61
/etc/X11/xenodm/authdir
. . . .


At the really end I get this: Locating unknown directories: ok

I don't understand what is with that list of "not found" files.
In the manual page it does not say much about this option (or I don't understand much), it only states: "-F Check the filesystem for random objects.".

Q1: What are those random objects?
Q2: It actually checks the file system?? (like fsck)
Q3: What's about that long list of not found directories and files?