About this question
I am using Person Accounts and have 2 custom objects: Ownership and Property.
The Ownership is a junction object and has 2 lookups: Account and Property.
I'd like to run a report with a filter that gives me unique Accounts where House.Type = 'Maisonette'. However when I run a report, I may get multiple Accounts because someone owns more than one Property which is a Maisonette.