Female referees Alhambra Nievas and Joy Neville will both take charge of men's international matches this year, becoming the first women to do so.
Spain's Neivas will officiate Finland v Norway in the second tier of the European Championship on October 14th.
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.