SELinux context file format

[Leif Thuresson]

I'm experimenting with creating custom SELinux users with specific
privileges.
I've read Dominick Grift article series about SELinux lockdown which I
found very helpful.
 
(http://selinux-mac.blogspot.com/2009/06/selinux-lockdown-part-one-confined.html)
What I'm still missing is a detailed description of the SELinux context
files and format.
Although I can guess the use of certain fields I don't feel comfortable
with just copying
a context file for a built in user without understanding exactly what
I'm doing.
Can someone point me to some documentation of the context file format?
(I'm using Fedora12 for my experiments)
Thanks,
/Leif