As I only just joined the HOL team, I can't say what happened in the past, but you upload them to the FTP and they will be processed if they are suitable. Otherwise I (or another team member) will inform the uploader (as long as it's clear who he is), that there's something wrong and how to fix it. There are still uploads that need to be processed, but I try my best to find some time to add them. It doesn't hurt if you announce your contribution here however
