This is a question about XP: this is not a real experience, but I want to have only an idea about PM rules.
I've found a user with a great number of downvoted nodes. I've seen his homenode, he had written many nodes downvoted but his XP is: "none earned". It is possible to have a negative XP after writing downvoted nodes? There's a limit (in nodes or in negativity) for this behaviour?