The Nations Cup is a rugby union competition that was first held in 2006 at Estádio Universitário in Lisbon with Argentina A, Italy A, Portugal and Russia taking part. From Wikipedia
World Rugby set to introduce major system changes starting from 2026, including expanded World Cup, alignment of international calendars, and new biennial Nations Championship; proposal faced mixed reactions as critics underline favoritism towards traditional rugby powers and delayed promotion/relegation until 2030.