I've found that many lists I use include IP addresses along with typical hostnames. Though I know my Pihole does not filter them, I don't like the fact that they exist in my list, take up 50K lines in a 3M line file, and that they are useless as Pihole will never be able to do anything with them.
I've seen plenty of regex strings that can identify strictly IP addresses (or URLs only so nothing unwanted finds its way into the file), so I'm curious if it's possible to add this feature in the future. I've been trying to figure out why my Pihole seems to die at night, and it's something I've noticed in the gravity.list file.
Thanks! (Ignore the part about the Pihole dying at night, when I care to dig into it further, I'll make a separate post about it given that I'm not finding anything specifically wrong, and systemctl restart pihole-FTL && pihole -g seems to fix things up quickly).