License Screening

Dear All,
I'm configuring licenses for license screening. Can you someone help me what is the exact purpose of selecting User Defined Codes (Category etc) in license screening page? What is the impact it has on the license screening?

I also have one more question. I understand the involved parties are screened based on AND condition. Is there a way i can do a screening based on OR condition between Source and Destination location?

Thank you in Advance!