Though the text may seem cut off (incomplete), all three gamerules do work. It's not really /gamerule but instead sets a repeating command block commanding the game to perform an action to certain cases. Suppose a cmd block commanding: Any dropped item will be teleported to the rabbit named "Trash". That can be useful for preventing dropped items go all over the place- after a second they all teleport to the trash bunny. There are also two other gamerules too.