Wait, what is a PreDB?
As listed in the Scene Glossary,
A database with all release titles. These release titles are not for download, they are just records.
Apart from the release title, a record often also contains the release size, release date, and sometimes also NFOs.
With commands one is able to 'check' a release.
Pre IRC Channels
SubReddit for new Game Release announces, also have game piracy news/discussions.