Blank "Host" field = proxy server? Possible to block these registrations?

[nwflyboy]

I'm getting pretty tired of processing account registrations by spammers (and I'm pretty stubborn and dedicated).  Today, I've probably denied and banned 50 registrations (and I expect a dozen more before I call it quits for the night).  Most of these are exactly what you would expect: spammers from Ukraine or Russia (one registrant today was legitimate).  For all these spammers, almost without exception, the "host" field appears blank.  I have some questions about that...

When the registrant's "Host" field is blank, does that mean they are using a proxy server?

In my experience, when the Host field is blank, it's ALWAYS a spammer.

Is it possible to reject any registration with a blank Hosts field?

Thanks.

[YogiBear]

It means the IP cannot be resolved to a particular host but I've found not all such registrations are bad news.

IMO a better route is to install an anti-spam mod or two but you do have Verification Questions built-in to v2.0 which keeps out most robots and slows down the human spammers quite a bit.

[Arantor]

It might mean they're using IPv6, which SMF does not current support.