You can use your flag with the /flag Country command.

Available flags:

Korea
Albania
Algeria
Arab Emirates
Argentina
Australia
Austria
Belgium
Bosnia
Brazil
Cameroon
Canada
Chile
China
Colombia
Ivory Coast
Croatia
Czech
Denmark
Egypt
England
Finland
France
Germany
Ghana
Greece
Honduras
Hungary
Indonesia
Ireland
Israel
Italy
Japan
Korea Republic
Kosovo
Lithuania
Luxembourg
Macedonia
Malaysia
Mexico
Netherlands
New Zealand
Nigeria
Norway
Paraguay
Peru
Philippines
Poland
Portugal
Romania
Russia
Saudi Arabia
Serbia
Singapore
Slovakia
Slovenia
South Africa
Spain
Sweden
Switzerland
Thailand
Turkey
United Kingdom
Uruguay
Usa
Venezuela
Vietnam
Armenia
Azerbaijan
Bahrain
Belarus
Bolivia
Brunei
Bulgaria
Burma
Cambodia
Cyprus
Dominicanrepublic
Ecuador
Elsalvador
Estonia
Faroeislands
Georgia
Guatemala
Iceland
India
Jamaica
Kuwait
Laos
Latvia
Lebanon
Moldova
Monaco
Montenegro
Morocco
Newcaledonia
Oman
Parkistan
Panama
Puertorico
Somalia