Comment 8 for bug 284250

This can be annoying for users behind company firewalls, where the company has hosts both inside and outside the firewall that are in the same domain - eg they're all *.company.com. The only way to distinguish between intranet and internet hosts is using the subnet - unless you list every single combination on the subnet (or just try to maintain a list of IP addresses for each host that fails).

I would dispute the 'low' importance. This is actually 'quite' important...bordering on 'very'.