For stock items only, enter the account that the inventory for this item is charged to. This account is used as the default account for entering purchases. Generally, the account gets debited when you purchase more of the item and credited when you sell the item.
To display a list of existing accounts, type ? in this field, or select the Lookup button. To add a new account, type + or double-click the field, which displays the Maintain Chart of Accounts window.