Not all TPGs are the same. From your question, I presume you're talking aout PCGS. "are they cleaned" ? Some are, some aren't. All of the more recent PCGS "genuine" slabs have a code which indicates why the coin didn't receive a grade. Here is the link which shows the code meanings : http://www.pcgs.com/grades.chtml Code 92 means "cleaned". The code is on the certificate. There is a 4-digit number, a period, then a two-digit code. That's what you're looking for.
