1. Reference book → Warehouse → Operation Types Create separate operation types for purchases and sales by filling in the “Activity Type” and “GPAIS classifiers” fields. In the sales operation type, fill in the “Activity Type” field by selecting the appropriate option from the list. In the purchase operation type, fill in the “GPAIS classifiers” field by selecting the appropriate option from the list. Don't forget to link the created sales operation type with the document series in Reference book → Warehouse → Doc. series 2. Register a purchase or sale using the created operation type: Warehouse → Sales – click Register a sales entry as usual. After selecting the newly created operation type, the “Method of operation” field is filled in automatically. Warehouse → Purchases – click Register a sales entry as usual. After selecting the newly created operation type, the “Method of receipt” field is filled in automatically. Note: Creating a separate operation type is not mandatory. However, if you do not create one, you will need to manually fill in the “Method of operation” and “Method of receipt” fields during purchase, sale, or write-off operations.