Classes
The Classes topic might be the most important one : this is the root of the whole Class/Instance hierarchy, heavily used by Goozzee for its inner working.You'll notice that the right-hand buttons area of this topic is almost empty (apart from its link to the Root topic), although you can link this topic to whatever you find useful. In fact, the interesting stuff is on the left-hand buttons area : that's where you are going to navigate the Classes hierarchy. This buttons area is divided in two parts : the upper contains the Classes – i.e. the parent classes of the current topic –, while the lower part contains the Instances – i.e. the child classes of the current topic.
You'll see that the Classes topic has no parent class, and you can't add any (since this topic is, and must remain, the top of the Classes hierarchy). But the Instances area is already filled with a predefined association : the Metadata. (See Classes and Inheritancefor more info about Classes and Instances).