Comment # 11 on bug 1031295 from Ladislav Slez�k

(In reply to Ludwig Nussel from comment #9)
> Out of curiosity, how does yast know what to install there? :)

The pattern selection is a bit tricky, there are more possibilities. 

- The default patterns might be defined using the "defaultpattern" Provides 
  (see https://fate.suse.com/320199)
- In the past the default patterns were defined in the "content" file
- Some default patterns are also in the control.xml
- The addon-products might select additional patterns to install

But I do not know which case it is here, maybe there is even some more... ;-)