For Custom Order Orchestration, how to handle null value in line selection rule

In the custom Order Orchestration, we have requirement to filter the data for order fulfillment based upon EFF Values "Y", "N" or null and for that we are using condition in line selection criteria. We have to handle null value also in such a way if any order line populated for existing order or new order with blank value of EFF Field, condition should validate null value and execute the result similar to "N" Value.