To get a trust¹⁾ on QuakeNet, the hostname your IP resolves to must be non-generic. The reason for this is that if it is generic, QuakeNet has no way of telling wether or not it is dynamic or static. Sure, you could tell them what it is, but that simply isn't enough. A second option would be for QuakeNet to contact your ISP, but that would really be a waste of their voulentary time and QuakeNet can't be sure that information is accurate either.

When is a hostname generic? Most users who are rejected a trust on QuakeNet due to the fact that their hostname is generic, think QuakeNet are claiming their IP to be dynamic, that is not the case at all.
The easiest way to illustrate exactly what makes a hostname generic, is some examples:

Generic:

p5487CC29.dip.t-dialin.net
d137-186-214-116.abhsia.telus.net
a81-14-130-202.net-htp.de
cc161732-a.hnglo1.ov.home.nl 

Non-generic:

something.something.else.com
fancy.vhost.outa.my.way.dk
just.a.last.example.to.prove.my.poi.nt 

As seen above, a hostname is non-generic when the IP resolves to a custom vhost (vanity host). And generic when the hostname is made up of seemingly random sequences of numbers and letters, sometimes the IP itself is part of the hostname.

If your ISP always give you the same IP when your router/modem connects to the internet, it is a static ip. Static ~ It never changes.

When your ISP doesn't always give you the same public IP when your router/modem connects to the internet, it is a dynamic ip. Dynamic ~ It changes.

Internet Service Provider. The company who provides you with access to the internet.

What your IP resolves to when a DNS lookup is performed on it. Sometimes refered to as a hostmask, vhost, vanity host, host. If you use mIRC you can look up your own with, /dns <your ip>.