For the first time in history, a referee issued a white card during a football match in Portugal.

If you have any knowledge of football, you know that referees traditionally use yellow cards (for warnings) and red cards (for permanently suspending a player from the game).

So it was a surprise to people when a white card was shown during the Women's Cup match between Sporting Lisbon and Benfica.

The white card, also known as the "fair play card", was introduced by the Portuguese Football Federation and aims to promote sportsmanship. The card rewards positive behavior on the field.

So far only Portugal has adopted the white card and it remains to be seen if it will be used in other countries.

In the past, the green card has also been used in Italy's Serie B league and during the 2018 Conifa World Cup, which is an international tournament for countries not affiliated to FIFA.

The green card is used in some sports to signal a warning to a player who has committed a minor offense which is not serious enough to warrant a yellow card.