I forgot which serves use them, but on the servers that us country tags next to players names, chat tags and groups can't be shown. The country tag always displays over any chat tags equipped. For example, if I have the DMFrenzy Admin tag equipped, it displays fine on servers not using the country tags:
[DMFrenzy Admin] HitmanG
But on servers with the country tag, it never changes, so I will only ever display my country
[US] HitmanG
[DMFrenzy Admin] HitmanG
But on servers with the country tag, it never changes, so I will only ever display my country
[US] HitmanG