Let 'localhost' be localhost
Isn't there a problem here? This draft says:<p><i>IPv4 loopback addresses are defined in Section 2.1 of [RFC5735] as "127.0.0.0/8".</i><p>That's not perfectly true. RFC5735 defines 127/8 as loopback addresses, but it leaves the door open for other addresses to be assigned to the loopback interface.  And indeed doing so is a common pattern for network devices, and a less common (but very useful) pattern for services.<p>So let's say I've assigned 10.1.1.1/32 to a device loopback interface, I'm announcing it in my IGP, and I've bound a particular service to listen on 10.1.1.1:1234.  Should the local resolver library be allowed to return 10.1.1.1 for servicename.localhost?  Under this draft's (re)definition of loopback addresses, definitely not.  So now we've lost that symbolic way to configure a service consumer to connect locally.  You're left inventing workarounds such as your own namespace for loopbacks, or changing the service to also bind to, say, 127.1.1.1.<p>I also find it curious that this draft allows only address queries (presumably A and AAAA) under .localhost.  I'd like to know the rationale for that restriction.  For example, there may well be applications that <i>only</i> use SRV records.<p>Unnecessary restrictions can have unexpected & unknowable consequences. "Tools not policy".