Field CommissionRate (2646) - FIX Protocol FIX.5.0SP2 EP240
The commission rate when CommissionAmount (2640) is based on a percentage of quantity, amount per unit or a factor of "unit of measure". If the rate is a percentage or expressed in basis points, use the decimalized form, e.g. "0.05" for a 5% commission or "0.005" for 50 basis points.
Added in protocol FIX.5.0SP2 (204)