Regexp syntax

[Per Sjoholm <Per t Sjoholm flysta net>]

Updating from CentOS 4.7 to 5.2 with targeting and enforcing.
(Main reason for doing the update)

Were can I find the syntax description for the regexp used in semange 
fcontext.
And also some non trivial examples.

I have read
http://fedoraproject.org/wiki/SELinux/ManagingFileContext
http://docs.fedoraproject.org/selinux-user-guide/f10/pdf/Security-Enhanced_Linux.pdf

Thanks
Per