The only way to choose your internal namespace so that it doesn't conflict with external names is to use a namespace you own, because there are no reserved doma

The only way to choose your internal namespace so that it doesn't conflict with external names is to use a namespace you own, because there are no reserved domains for "internal" use. Specifically, that's going to mean that your internal names need to be subdomains of a domain name you control, such as your organization's domain. Something along the lines of "*.internal.companyname.com".