Secretz

Secretz is a group of mods which are closed-source and their in-game documentation is partially missing. According to CalebJ, there are two reasons why these mods are secret. The first reason is to make a part of server which cannot be copied by another server. The other reason is to encourage players to discover their functionality using in-game mechanisms and not by reading some kind of documentation. There are a few controversies about secretz.

What is actually secret?
The recipes and mechanisms which are not shown in the unified inventory are secret. Some people say that it is also forbidden or discouraged to speak about the recipes and mechanisms which were discovered by players.