This is what they do -

• Convert any sales orders in currency to your default currency on order list view and in reports
• New Product Costing and Raw Materials - convert any Make/First costs or Raw Materials unit cost into default currency for costing *
• Convert any Purchase Orders values from the currency listed into your base currency value in PO List View and Reports
• Convert any Production order values from currency value into default currency value in Reports

When creating a new season, it is helpful to consider -

• Amending exchange rate in Settings for the exchange rate you wish to use for conversion for the season
• Actions after bringing forward products and raw materials from other seasons