I'm getting closer!
- The ticked categories are stored in the W-Key of the active technology (<default> = Global Resources)
- The unticked categories are stored in the B-Key
So I do the following:
0. Technology is set to <default>, All the actegories are active (meaning Global Resources::ModelValidation::W contains all of them, ...::B is empty)
1. By "Configure..." I unselect whatever categories I don't want to run in the validation
Unfortunately (!!) after pressing OK the keys remain the same...
2. I Change the Technology to something else than <default>
Now the Global Recources-Keys are updated. (Ticked categories in W, unticked in B)
3. So I go back to <default>