Rugby union laws allow referees the option to send a player off for 20 minutes.
But once the time period is over, the offending team can send on a replacement in their place.
It was brought in by World Rugby following a successful trial at the Autumn Nations Cup in November last year.
This type of red card is given for technical offences, such as accidental head contact, rather than a deliberate or dangerous act, and designed to punish the player and not the team.
So how does it work?
If a red card is shown to a player, they must leave the pitch for the remainder of the match. But 20 minutes after the red card is shown, the punished player can be replaced by a team-mate.
This enables a team to return to a full complement of players on the field.
Referees are still able to award a permanent red card for “deliberate and dangerous acts of foul play”, with no replacement allowed.
The law was also trialled at the 2025 Six Nations, and will be in place for the Women’s Rugby World Cup in August and September.
This article is the latest from BBC Sport’s Ask Me Anything team.