-r means running, it shows the version of the currently running kernel while -k shows the version of the installed kernel (that would be booted). If they disagree, you must reboot eventually.
-p5, the kernel version would show -p5 as well.uname. The manpage should make explicit that this tool will only show the kernel version and that this version doesn't need to be up-to-date with the currently installed freebsd version.freebsd-version also seems be be causing confusion.
I am of the same opinion.
It shouldn't. By default, it prints the userland version, which is the relevant information most of the time. The manpage also documents the fact that the kernel might have an older version.
By default, there is only one. But being able to know the versions of both the installed and the running kernel is helpful, for example to know whether you must reboot.
And that's where I say: I think it's
uname, at least for those who do read manpages. uname is the canonic (unix) tool to know the system version, so especially if you don't know FreeBSD deeply yet, it's probably the first thing you try. And the uname(1) manpage doesn't make it explicit enough that it is the version obtained from the running kernel, neither does it mention that the kernel isn't updated with every patch release (like the freebsd-version(1) manpage does).It's how it should be for me. Uname is a generic posix tool, freebsd-version is not.
NOTE
Usually, the user needs to be prepared to reboot the system. To know if the system requires a reboot due to a kernel update, execute the commands freebsd-version -k and uname -r. Reboot the system if the outputs differ.
uname (because, yes, it is the "standard" tool you already know from other systems), you're confused. We can't help people who just don't read any docs of course, but say you're not one of them, which document are you most likely to read? Probably uname(1), don't you think? That's why I think it should be improved on that topic...
freebsd-version -kru though, you're good to go.