This summary is not the rule. The rule text controls.
If your case involves a law from another country, you need to tell the other side and the court ahead of time. You can do this in your written court documents or through some other clear written notice. You cannot spring a foreign law issue on the other party at the last minute without warning them first.
When the judge needs to figure out what a foreign country's law actually says, the judge has a lot of freedom in how to research this. The judge can look at almost any helpful information, including expert testimony, even if that information would normally not be allowed as evidence in court. This gives the judge more flexibility than usual because foreign law can be hard to research and understand.
Finally, once the judge decides what the foreign law means, this decision counts as a ruling on a legal question, not a factual one. This matters because it affects how the decision can be appealed later. Legal rulings are reviewed differently than factual findings if someone challenges the outcome in a higher court.
