"An institution may select the standard to apply on a case-by-case basis"

How are you interpreting 'case-by-case'? We took it as loan-by-loan but some are thinking differently.

More specifically, this is in regards to reporting a multi-use property.

Who took it differently and differently how and based on what?

I'm assuming your referring to whether a mixed-use property is a dwelling. I would agree that case-by-case is loan-by-loan, or more specifically property by property. Each situation is different. Sometimes the standard used for one property would make no sense on a different property. If it's a close call, I'd document your file with how you made the determination. If you're using different standards to try and avoid reporting, then you'll probably find some trouble. Do what makes sense for the property in question.

I also agree that it is loan by loan. In addition to what IR state, you have to look at how the borrower uses the property (or plans to use it) to determine if the property is primarily a dwelling or not.