Warren Gatland has insisted that Wales did not break any rules by including players outside of their World Cup squad in their training session on Wednesday.
Wales are reported to have used eight players who did not make the final 31-man squad in preparation for Saturday's meeting with Pool A rivals England at Twickenham, and World Rugby responded by handing them an official warning.
Tournament rules stipulate that only the players who are selected for the squad can be present at official events such as training sessions and match days.
"We haven't broken any rules," the Wales coach told reporters. "Apparently we have broken the 'spirit of the rules'.
"What that means we don't know. I don't know what we have done wrong."
Wales started their campaign by beating Uruguay 54-9 in Cardiff on Sunday.
