Robert evaluated other category systems and tried to imitate the best he found and to avoid the mistakes they contained. He explained the various fields that you find in the category administration an how you can use them in your own module.
The system was considered quite complex by the audience but Mark West and Robert assured that this will be taken care of. The use of basic categories will be as easy as possible.
But first of all the system works and can be used by the module developers. It is also their duty to create intelligent user interfaces for the categories in their modules.
There are basic plugins available that display category lists aso. Further plugin can be developed on demand of the community. So if you feel there's something missing - make it a feature request in the NOC.
During the discussion various ideas for simplification came up and will certainly be implemented among of which were the security domain, the custom data fields and the needed -1 value for main categories.
Robert also explained that it is also possible to put for example one article into several categories.