How does one become a Herald?

I've noticed some people around the forums with a Herald shield next to their name, and read the page following the link. I remember hearing the initial discussions about this position.

So I'm wondering, how does one apply to become a Herald? The page explaining the role shows me a list of pages that don't yet have Heralds, and I was thinking of perhaps applying for one of the positions, but the page doesn't show the procedure for applying, or what the criteria for the message are, or anything like that.

I searched the forum for any other titles with "herald" in the name, so if I somehow missed an official thread detailing this, I'm sorry.

The thread is here.

Thanks. I suppose I should've Googled a bit harder, but thanks for the redirect.