Rules Which Make NO Sense

How do you indicate more than one halo? Is it "halos" or "haloes"?

Turns out, it's BOTH. Talk about a stupid rule. How do I know which my editor wants? I don't want to pester her with silly questions, but I don't want to use a version she will consider incorrect, either.

This is definitely one of those rules that makes non-Wordgeek types hate grammar--and even some of us wordgeeks, too.