If I purchase a prepaid voucher to be converted to cash within a year, what category of accounting that should I use in Odoo when I want to reconcile my account ? In the old system that I use before (not Odoo), I have a chart account where I can define the category as  'stock purchase'. Now I need to reconcile the purchase of prepaid voucher that I made using BANK payment (that need to be reconcile), and I don't know which category of account it should belongs to. Is it an expense category ?