My parents grew up there back wen the Irish were the...well,”undesirables” of Boston.My father’s older brother used to tell stories about hiring halls having signs saying “no Irish need apply”.
He must have been born a long time ago. Lots of Irish have stories about NINA signs, but the signs were around back in the 19th century.
If you look up old Boston Globe help wanted ads from as late as the 1960’s you will see the occaisional “NINA” in the ads.