anchor.diff:  
   
   // ----------------------------------------
  -// ------ X-OCCI-Attribute attribute ------
  +// -------- X-OCCI-Attribute Header--------
   // ----------------------------------------
   /*
   
  
positive.code: ;
  
  // ----------------------------------------
  // ---------- Category attribute ----------
  // ----------------------------------------
  
  /*
  ABNF representation of category from the http rendering specification
  
  
negative.code:   CLOSE_PATH = '>';
  }
  
  // ----------------------------------------
  // ---------- All OCCI Headers ------------
  // ----------------------------------------
  
  occi_header:
      category_header
    | link_header
  