Gregory's Server
when i was doing tech support for an open source DNS server, we regularly got support customers wondering why using fake roots or fake DNS names that collided with the public DNS kept breaking things.
i also worked for a large ISP that really pushed using IPv6 because they'd had problems in their NOC with many reuses of RFC1918 space and address collisions.
RFCs are not for the faint of heart but they have lots of good info and lots of reasons why you should follow them. ;)