Ah the filter is called "Not Installable". You may have to add it if it's not
there - Settings --> Filters --> New --> Name it "Not installable" and only
check that option.
However the problem then is that if some of them get removed they want to
remove stuff you actually do need. On a default installation that seems to
just be "tzdata".
You also want to add a filter for "For removal" and then after you do the
first thing select all and mark for *complete* removal to get rid of.
Otherwise check a residual config filter.
For me it took several run-throughs of going to Not installable and going to
"For removal" and going to "residual config" and finally going to "auto
removable" to make sure everything was really gone.
Just not sure about tzdata.
