A formula field can be used to SWITCH a country name to it's corresponding flag emoji (full formula below)
This can be handy to add a visual cue to a country and works nicely when added in record summaries like below/
This formula will include your flag emoji and using \n you can list other record attributes with a new line
"☑️ " &{SOME_OTHER_FIELD}&"\n"&"☑️ "&{YOUR_COUNTRY_FIELD}&" "&{FLAG} 
SWITCH for Flag
SWITCH( {YOUR_COUNTRY_FIELD},
"Afghanistan", "🇦🇫",
"Åland Islands", "🇦🇽",
"Albania", "🇦🇱",
"Algeria", "🇩🇿",
"American Samoa", "🇦🇸",
"Andorra", "🇦🇩",
"Angola", "🇦🇴",
"Anguilla", "🇦🇮",
"Antarctica", "🇦🇶",
"Antigua & Barbuda", "