anchor.diff:  "Corvo Island, Portugal ",CVU
   "Cotabato, Philippines ",CBO
   "Cotarou, Benin ",COC
  -"Coteau, QC - Rail service ",XGK
   "Courtenay, BC ",YCA
   "Cox's Bazar, Bangladesh ",CXB
   "Cozumel, Mexico ",CZM
  
positive.code: "Ostersund, Sweden ",OSD
  "Ostrava, Czech Republic ",OSR
  "Ottawa, ON - International ",YOW
  "Ottawa, ON - Rail service ",XDS
  "Ottumwa, IA ",OTM
  "Otu, Colombia ",OTU
  "Ouagadougou, Burkina Faso ",OUA
  
negative.code: "Denizli, Turkey ",DNZ
  "Denpasar Bali, Indonesia ",DPS
  "Denver, CO - International ",DEN
  "Dera Ghazi, Pakistan ",DEA
  "Dera Ismail Khan, Pakistan ",DSK
  "Derby, Australia ",DRB
  