Please add Irish to the list of Nationalities.
Do you mean the list of languages as can be assigned to names?
Or do you mean somewhere else?
Echoing Gordon: what list of nationalities? As he said, there's the list of languages for names, but that's not at all the same thing as "nationalities".
We've been trying to get Latin added to the languages for years now, since there are so many genealogical records written in Latin, but there has been no response from anyone at FS. Therefore, I don't know what the chances are of getting Irish Gaelic added to the list.