World Rugby will extend the residency requirement to switch national teams from three to five years from the end of 2020 in a reform aimed at protecting the "integrity and sanctity" of the international game, the global governing body said on Wednesday.
The change, which has been pushed by Argentine Agustin Pichot since he became World Rugby vice-chairman in 2015, was passed unanimously by the World Rugby Council at a meeting in Kyoto ahead of the 2019 World Cup draw.
The reform, which comes into effect from December 31, 2020, means players will have to reside for an extra two years in a country before becoming eligible to play for it - as scores have done in the decades since the game went professional.
Australia over the years has had its share of players who have turned out for other countries either at junior or senior level before wearing the green and gold including Clyde Rathbone, Dan Vickerman (South Africa) and Will Skelton (Samoa) and Tevita Kuridrani (Fiji).
The likes of Craig Wing (Japan), Craig Gower (Italy) and Dan Parks (Scotland) played rugby or rugby league in Australia before representing a foreign country.
The British and Irish Lions squad for the Test series against the All Blacks in June and July, for example, contains New Zealand-born Jared Payne and South African-born CJ Stander, who both qualified to represent Ireland on residency grounds.
"This is an historic moment for the sport and a great step towards protecting the integrity, ethos and stature of international rugby," former Pumas captain Pichot said.
"National team representation is the reward for devoting your career, your rugby life, to your nation and these amendments will ensure that the international arena is full of players devoted to their nation, who got there on merit."
In additional changes, the World Rugby Council voted to make players with "10 years of cumulative residency" eligible to play for that country with immediate effect.
There were also changes instituted to prevent countries from capping players who are eligible to play for more than one national team as youngsters in order to prevent them from playing for another nation.
From July, Sevens players will only be "captured", or identified as having represented a country and therefore forced to go through the residency period before switching, under two criteria.
They must be 20 years old when they play for the senior sevens team of a country or represent a country at the Sevens World Cup or Olympics having reached the "age of majority".
From next year, countries will also be banned from nominating their under-20 side as their "next senior national representative team".
