I work for a certain Unix vendor. Our network infrastructure is pure Unix, and all our DNS servers use BIND. No AD. That's not going to change.
When I plug a Windows PC into this network, it gets a FQDN that looks something like dhcp0131.westcoast.unixco.com, and a connection-specific suffix of westcoast.unixco.com. This works fine if I access another system in the westcoast domain. But outside that domain, only FQDNs work. So if I follow a link to boston.eastcoast, my browser chokes, and I have to hand-edit the URL to add the missing unixco.com.
Why so many partial domain names? Because most people are still using Unix or Linux, and these systems have no trouble figuring out that boston.eastcoast is shorthand for boston.eastcoast.unixco.com. I could hand-configure my own PC to add unixco.com as an additional suffix, but that doesn't solve anything for other PC users. I'd like to be able to suggest a simple change to our Windows-ignorant IT people that would support PCs properly.
I maintain a server (call it wiki.westcoast.unixco.com) and in order to ensure that anybody who links to it uses a URL that works everywhere within the company, I've configured apache to redirect any URL that doesn't include an FQDN. An ugly solution, and one I'd like to deimplement.