uname -r: release level

[Chris Stankevitz]

Hi,

I just setup my freebsd machine and performed a "freebsd-update fetch
install" which leads me to believe I am now running 9.2-RELEASE-p2.
Of course I wanted to see for myself using "uname -r" which reports my
"release level".

"uname -r" is reporting 9.2-RELEASE which is not quite what I was
expecting (I was expecting a p2 suffix).  That doesn't interest me too
much, but this does:

By what mechanism does "uname -r" determine my "release level"?

Thank you,

Chris