[CentOS] how to protect RT repository?

Tue Oct 16 20:54:41 UTC 2007
Rogelio <scubacuda at gmail.com>

I'm following the instructions on this URL

http://wiki.centos.org/HowTos/RT_3.4.x_On_CentOS_4.x

and came across the part that said

"WARNING: RT overwrites some packages from the base distribution,
especially mod_perl"

How exactly do I "protect" the RT repository?

It links to the "ProtectBase" program

http://wiki.centos.org/PackageManagement/Yum/ProtectBase

...but what do I mod to protect this RT repository?