I understand it is a mistake by my side. But I unintentionally did not mention the refusal. Otherwise, I would hide all refusals especially I have a new passport now. The US embassy should have written down a reference on my passport so I can get back to otherwise anyone can forget something that happened 8 or more years ago. Is there anything that can help me with my situation and I can mention?You have to mention them every time you apply...….failure to mention on an application (a legal document) when it asks (and it doesn't specify a time limit) is misrepresentation. That's why you received a PFL. If you had mentioned the US refusal this time, I doubt a PFL would have been issued (as long as you disclose before IRCC finds out, they seem to give you a pass).