Self Support

Hi,
Can someone please explain what is meant by,
"Can only be deployed on physical systems." in Red Hat Enterprise Linux Server self-support license? does that mean, we cannot use Red Hat Enterprise Linux Server with a self-support license inside a virtual instance (probably instances created by VMware or virtual box)?

Further, can someone explain why exactly self-support license is labeled as not to use in production? is that because of the service levels granted to the self support is low compared to the other subscriptions?

Regards