What are these strange whitespaces?

These are not libraries in the traditional sense; "Critical system files"?

I see no subdirectories instantiated after install.

Using a memory-based system for /var seems like a really bad idea; logs and accounting files should be preserved after a reboot. /var/run and maybe /var/tmp might be OK, although the latter would make vi file recovery impossible after a reboot. I think we should just delete the memory-based file system info. Oh, /var/mail is another example.

See above about /var being memory-based.

This naming is only true of bsdlabel-based partitions, which are used less and less (not with gpt). I'm not sure how to fix this without adding confusion, but maybe we need to mention MBR and GPT conventions.

I would add: A file system can only be expanded into free space in the partition in which it resides. If there is space after the partition, the partition can be expanded with man:gpart[8]. If the partition is the last one on a virtual disk, and the disk is expanded, the partition then be expanded.

Followup: I propose doing some work on this in a separate review.

This is UFS-specific. I propose this.

Should be "is", not "are".

There is some strange spacing in this section.

s/do/done/

Looks like the period here should still be a comma.

Should this part be retained? 9.x is quite old now.

The last clause is missing a word; "can then be expanded".

I think we should document the symbolic way to set this first, then include the octal.

As above.

Similar to set[ug]id, I think we should document the symbolic method first.

A mistake, hehe.
Fixed on commit.

In my laptop:

ls /media
Generic_Flash_Disk_04D18A60 Generic_Flash_Disk_9F316B8F_s2
Generic_Flash_Disk_9F316B8F Generic_Flash_Disk_9F316B8F_s2_s2a
Generic_Flash_Disk_9F316B8F_s1

Yes, I'm gonna commit this review and we can work on this in a separate review.

I'll fix this on commit. Some problem with copy&paste in Visual Studio Code.

Also removed the reference to FreeBSD 10.

ls /media
Generic_Flash_Disk_04D18A60 Generic_Flash_Disk_9F316B8F_s2

These are leftovers from sysutils/bsdisks. Which I should fix and make it remove empty directories.

Is this the ideal location for the warning? It struck me as strange that we are warning about a group before groups have been introduced

Should we add something similar here about bsdconfig(8) for users who want to do this sort of thing with a curses interface?

Focusing on the line for myfile, the first character indicates whether this file is a regular file, a directory, a special character device, a socket, or any other special pseudo-file device.

I don't see how to edit my suggestion, but I meant to keep (leftmost) after first.

I'll add this in a separated review. Good idea to add this :)

I got the text from https://www.freebsd.org/cgi/man.cgi?query=hier&sektion=7&format=html, if it's wrong, we need to upgrade the manual page too