This has never happened to me but it was an incident I thought of and I don't know what would be acceptable.
If there was a player who had English as their second language. You give a decision against them and they say something in their first language. Presuming you don't also speak their first language and you don't know what they are saying which means they could be saying something which would normally result in a red card but you don't know about it. Would it be acceptable to tell them that if they want to say something to you then they say it in English otherwise it will be classed as dissent and they will get a booking?
If there was a player who had English as their second language. You give a decision against them and they say something in their first language. Presuming you don't also speak their first language and you don't know what they are saying which means they could be saying something which would normally result in a red card but you don't know about it. Would it be acceptable to tell them that if they want to say something to you then they say it in English otherwise it will be classed as dissent and they will get a booking?