Notional's governance can set an additional fee rate that increases the borrow interest rate of leveraged vault borrowers. The fee is denominated in 5 BPS. Such that a feeRate5BPS of 10 would imply that leveraged vault borrowers are charged an additional 0.50% in interest on top of their trade implied borrow rate.
These fees are then split between nToken holders and the protocol's reserve based on the reserveFeeShare parameter. A reserveFeeShare of 80 would allocate 80% of the generated fees to the protocol's reserve.