There's no working way to add information about custom flags via override/*.spec.
The inifile format does support multiple section with the same name, so it's not a problem to have the new section in the override .spec, but there's no way to extend existing list (in this case: "sprites"). Assigning a new list causes the existing entries of the list to get replaced. So when one adds one custom nation flag, abkhazia flag information disappears.
There's no working way to add information about custom flags via override/*.spec.
The inifile format does support multiple section with the same name, so it's not a problem to have the new section in the override .spec, but there's no way to extend existing list (in this case: "sprites"). Assigning a new list causes the existing entries of the list to get replaced. So when one adds one custom nation flag, abkhazia flag information disappears.