After upgrading my pi-hole from version 4.0 to version 5.0 I went ahead and deleted all the adlists in order to run
pihole -g to update the database. What I didn't realize at the time, was that pi-hole still has to rely on a list of adlists to populate the database.
After searching for a couple of hours on the internet for a list of default adlists provided with the initial installation of pi-hole, the only reference I found was a screen shot on the GitHub page.
The screen shot contains the following items:
https://sysctl.org/cameleon/hosts (actually without SSL)
https://zeustracker.abuse.ch/blocklist.php?download=domainblocklist (results in zero additons)
I couldn't find this list in written form anywhere in the pi-hole documentation or in the forum.
Would it be possible to add an actual list of the default adlists you provide to the documentation section of pi-hole?
While this topic might be an actual feature-request, I have placed this topic in the General | Customizing Pi-hole section for everybody to discuss.