Hi Rutledge

Top level domain means "mydomain.com" and in addition we normally allow one subdomain (e.g. "www.mydomain.com" or "store.mydomain.com" ). We accept subdomain aliases that point to the same site within reason. We also allow an additional test/stage domain (e.g. "mydomain.dnndev.me", "test.mydomain.com" or "localhost" ). 

If you have multiple subdomains, you will need a separate license. I hope this helps to clarify.

Thank you