anchor.diff:  KOTH,North Bend,Oregon
   KOWB,Owensboro,Kentucky
   KPAH,Paducah,Kentucky
  -KPBG,Plattsburgh,New york
  +KPBG,Plattsburgh,New York
   KPBI,West Palm Beach,Florida
   KPDX,Portland,Oregon
   KPGA,Page,Arizona
   KPGD,Punta Gorda,Florida
  -KPGV,Greenville,North carolina
  +KPGV,Greenville,North Carolina
   KPHF,Newport News,Virginia
   KPHL,Philadelphia,Pennsylvania
   KPHX,Phoenix,Arizona
  
positive.code: KPVD,Providence/Warwick,Rhode island
  KPVU,Provo,Utah
  KPWM,Portland,Maine
  KRAP,Rapid City,South dakota
  KRDD,Redding,California
  KRDM,Redmond,Oregon
  KRDU,Raleigh,North carolina
  KRFD,Rockford,Illinois
  KRHI,Rhinelander,Wisconsin
  KRIC,Richmond,Virginia
  
negative.code: ICAO,City,State
  KABE,Allentown,Pennsylvania
  KABI,Abilene,Texas
  KABQ,Albuquerque,New Mexico
  KABR,Aberdeen,South Dakota
  KABY,Albany,Georgia
  KACK,Nantucket,Massachusetts
  KACT,Waco,Texas
  