This is a clip from man shutdown, it doesn't completely answer
you question but I think its going in the right direction.
Code:
The -F flag means ‘force fsck’. This only creates an advisory file
/forcefsck which can be tested by the system when it comes up again.
The boot rc file can test if this file is present, and decide to run
fsck(1) with a special ‘force’ flag so that even properly unmounted
filesystems get checked. After that, the boot process should remove
/forcefsck.