CentOS - May 2005 - packages in centos-3.3 base changed

Hi all,

Correct me if my understanding is wrong.  The [base] repository of 
centos-3.3 will never change after release.  All future updates should 
go into [update].

I have an autobuild system to build a production server.  If the [base] 
repository will never change after release, then I can maintain the 
reproducibility of the production server by always installing from the 
[base] of centos-3.3.

Regards,
Leonard Ye