Documentation on spam detection/protection features

Can you please provide a quick rundown/brief explanation of the spam protection features on the backend? I see this thread and this one and some code in /backend/app/cmd/cleanup.go that relates to spam, but I'm not certain what exactly is implemented and how it should be used.

Thanks!

Here is the current spam detection, there is nothing aside what's written in this check currently.

The documentation is published here.