Against each Tide Field in the Review step grid there is a Specify Default button. Selecting this button opens the default value modal window. Here you can enter rules for populating the Tide Field with a default value.
Your first option is to enter a default value if the field is blank. This is entered against the field 'Default value if Conditions are not met'. If no Bordereau Field has been assigned to the Tide Field, then this will always apply. If a Bordereau Field has been assigned to the Tide Field, then this will apply if the field is blank.
You can also enter conditions, that if met result in a different default value; these are called Conditional Defaults. In essence, this means you can set rules that if 'X' is in Bordereau column 'Y', then put default value 'Z' into the selected Tide Field.
To create one, select Add Conditional Default. Then select the Bordereau column that this default will be based on. Select an Operator of Equal to or Not Equal To. Then enter the value of the Bordereau column that this is based on, and then finally enter the Default Value that is to be populated in the Tide Field. You can enter as many Conditional Default rules as required.