Female referees Joy Neville and Alhambra Nievas to officiate men's internationals
Alhambra Nievas and Joy Neville will both take charge of men's international matches this year, becoming the first women referees in Europe to do so.
Spain's Nievas will officiate Finland v Norway in the Conference 2 division on 14 October.
Neville will take charge of Norway's match against Denmark two weeks later.
The former Ireland captain and Six Nations Grand Slam winner refereed the Women's Rugby World Cup final between New Zealand and England in the summer.
She also became the first female assistant referee to officiate in a men's European rugby match during last season's Bath and Bristol Challenge Cup game, and has also taken the same role in the Pro14.
Former Spain international Nievas became the first female match official in a men's Test when she was appointed assistant for USA against Tonga last year, and was later named Referee of the Year 2016 at the World Rugby Awards.
She also officiated at the rugby sevens at the 2016 Olympics in Rio.
Speaking to BBC Sport, professional referee Nigel Owens, who took charge of the World Cup final in 2015, said it was a positive step forward for women in the men's game.
"It's great to see a cross-section as men have been refereeing the women's game for a long time," said the Welshman.
"What's important here is that the two girls concerned have got here on ability - not for the sake of ticking boxes. The two of them are very deserving and they're there on merit and it's a huge thing to remember.
"It doesn't matter about the colour of our skin, whether you're a man or a woman, your sexuality or religious beliefs. None of that should matter one bit. If you're good at what you do, then you should have the opportunity to excel at that and referee at the level you deserve.
"These two are getting what they deserve from the hard work they've done."
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