UnderlyingPaymentStreamCompoundingInitialRate <42936> field
FIX 5.0 SP2 EP272
The initial compounding floating rate reset agreed between the principal parties involved in the trade. It should only be included when the rate is not equal to the rate published on the source implied by the floating rate index. The initial rate is expressed in decimal form, e.g. 5% is represented as "0.05".