anchor.diff:  === ICU Folding
   
   Folding of unicode characters based on `UTR#30`. It registers itself
  -under `icu_folding` and `icuFolding` names.  
  +under `icu_folding` and `icuFolding` names.
   The filter also does lowercasing, which means the lowercase filter can
   normally be left out. Sample setting:
   
  
positive.code:             }
          }
      }
  }    
  --------------------------------------------------
  
negative.code: UnicodeSet
  http://icu-project.org/apiref/icu4j/com/ibm/icu/text/UnicodeSet.html[here].
  
  The Following example exempts Swedish characters from the folding. Note
  that the filtered characters are NOT lowercased which is why we add that
  filter below.
  
  