34 selected
- Not filled in
- Cabo Verde (Cape Verde)
- Cambodia
- Cameroon
- Cameroon - Central African States
- Canada
- canda
- Cape Verde (Cabo Verde)
- Cayman Islands
- Central African Republic
- Central African States
- Ceylon(Sri Lanka)
- Chile
- China
- China Kinmen
- China Macau
- China Taiwan
- Colombia
- Comoros
- Confederate States of America
- Congo (Brazzaville)
- Congo Dem. Republic
- Congo Democratic Republic of the
- Cook Islands
- Costa Rica
- Croatia
- Croatia - Serbian Krajina (1991 – 1995)
- Cuba
- CUR
- Curaçao
- Curiosa
- Cyprus
- Czech Republic
- Czechoslovakia
- Czechoslovakia