A confirmed booking can be client work or internal work. Both use capacity, but only a role marked billable contributes to billable utilization and forecast revenue. Keep the role's billable flag with the booking when you build a report. A person's hourly bill rate alone doesn't make every hour billable.
Desk Staffing calculates forecast revenue from confirmed billable hours multiplied by the person's bill rate. Booked delivery cost uses confirmed booked hours multiplied by the cost rate, including internal work. Forecast margin is revenue minus that booked cost. These are scheduled-work forecasts, not invoices, payroll totals or recognized accounting revenue. All rates are fictional training values. When you compare people, check the hours as well as the rate: a cheaper hourly rate can still cost more when the proposed booking is longer.