Example: d=AT

Andorra = AD
Austria = AT
Belgium = BE
Flanders and Brussels = BEFLBRU
Bulgaria = BG
Switzerland = CH
Cyprus = CY
Czech Rep. = CZ
Germany = DE
Denmark = DK
Estonia = EE
Spain = ES
Finland = FI
Feroer Islands = FO
France = FR
Georgia = GE
Greece = GR
Croatia = HR
Hungary = HU
Ireland Rep = IE
Iceland = IS
Italy = IT
Lithuania = LT
Luxembourg = LU
Latvia = LV
Monaco = MC
Montenegro = ME
Malta = MT
Netherlands = NL
Norway = NO
Poland = PL
Portugal = PT
Romania = RO
Serbia = RS
Russia = RU
Sweden = SE
Slovenia = SI
Slovakia = SK
Turkiye = TR
Ukraine = UA
United Kingdom = UK