exclude or include ?

Exclude or include ?
That is BlackList or WhiteList ?

• Only BlackList.
  In this way we assume that the user want to index most of the pages.
• Only WhiteList.
  In this way we assume that the user only want to index only a few pages.
• Both BlackList and WhiteList
  We assume nothing in this way.
  But there is another problem:
  If an URL matches some rule both in BlackList and WhiteList.
  How to handle it ?BlackList first or WhiteList first ?
• about UI
  two tabs (one for WhiteList, one for BlackList) or
  one tab for both WhiteList and BlackList
• save /load
  Save the WhiltList and BlackList to an XML file.
  Load the list from the saved file.
  Maybe I could make it possilbe to load the file in Epiphany Extension.