I tried making overrides of the core fields in order to be able to change the ordering of both core and custom fields.
To do this, I select at FILTER: OVERRIDE NAME. Then I get an empty list. Then I select MAKE and I create a field with the name NAME.
When I save this, I end up with a new extra field, so that in de front end I have now two fields with NAME. (see the attachment).
It appears that the core field is still there and a new field has been added (which is not what I want).
What am I doing wrong?
SORRY!!! JUST FOUND IT. I DIDN'T CHOOSE THE RIGHT OPTION IN THE NEW FORMULAR AT FIELD TYPE.
THIS QUESTION CAN BE REMOVED.