Name collisions have the potential to create unanticipated results for organizations that use private namespaces. This document lists some of those potential results and specifies best practices for changing the way that private namespaces are used within organizations.
For namespaces that used a private TLD that is becoming (or is already) a TLD in the global DNS, mitigation best comes in the form of migrating the namespace to a namespace that is rooted in the global DNS. For namespaces that use name shortening with search lists, mitigation can come only by eliminating the use of search lists. Steps to achieve these mitigations also include long-term monitoring in the private network to be sure that all instances of names that might cause collisions are no longer being used.
The comprehensive mitigation for the problems of name collisions is to use FQDNs in all places where a domain name is used. In a network that is already using the global DNS, this means not using search lists. In a network that uses a private namespace, this means that the private namespace should be rooted in the global DNS, and should not be using search lists.