Hello Martins,
Thank you for your enquiry. The reason why Rate Gains / Losses setting is not in the HansaManuals is because it contains a lot of bugs that need to be fixed. If there is a record in the Rate Gains / Losses setting, then the maintenance will use that setting, if the Rate Gains / Losses setting is empty, the maintenance will use the Rate Gain / Loss setting.
if you need more information on this please let me know.
Best Regards,
David D.
HansaWorld Support