Maybe you can share how it is being used, or where it appears, if perhaps on a HUD statement?

The only time I've seen R D used in regards to real estate is Revolving Debt, and this really applies to the financing, not so much the closing.

Revolving Debt is the amount of active debt you are liable for. It's a credit arrangement that allows a customer to borrow against a pre-approved line of credit used to purchase a good or service. The borrower is responsible for the actual amount borrowed plus any interest due.

Hope that helps!