Subscribe to RHEL Server Optional sub-channel using RHN Certificate-based Subscription Management?

When using RHN Classic Subscription Management, it is possible to subscribe to the RHEL Server Optional (v. 6 64-bit x86_64) channel.

How does one enable access to the packages in this channel when using RHN Certificate-based Subscription Management?

On a related note, how does one download the packages in the RHEL Server Optional channel so they are available during an install?   In my particular example I would like to have the libselinux-ruby package available during install the so I can install puppet from the EPEL repository and be able to manage the system when it is finished installing.