I have tried to find in the OCC site a specific definition for what is a "customer complaint" I know that there are definitions in the various regulation, such as Reg E. But does the OCC have any further guidance?

I don't believe there is a definition as it could involve such a wide variety of issues. I would refer to this site for more information:

http://www.occ.treas.gov/customer.htm

One of the missions of the CAG is to assist customers of national banks who have complaints or other issues related to applicable banking laws and regulations. I think a complaint is a dissatisfaction with a product or service. That is broad as Randy noted, but it is meant to be. That is what they do. It doesn't have to be defined by regulation.

You may also look at the guidance for Retail Nondeposit Investment Product programs. I recall there being something about monitoring for complaints in there.

We put together a complaint policy a couple of years ago separating Reg E complaints, and general, verbal "your rates are too low" compliants, from more defined, written complaints for which we have a process for response and filing. If you email me at susan.norton@the1st.com, I will send you a copy.