It's annoying that ".internal" isn't one of these, since mDNS uses ".local" by default - I've seen a lot of orgs using that in particular to avoid exactly the mDNS clash.
I decided after much consternation to hijack ".home" for my home network although ".internal" was also in the running. I really wish they hadn't just ignored the actual existing usage of ".local" when they decided to reserve it exclusively for mDNS.
