无需记录销往单位，无需填制销售货凭证，在计算机管理系统中为了分类统计客户群，可对某类客户做一标识，并且可由打印机打印出销售小票-No record of units sold, sales of goods without填制certificate, in the computer management system in order to keep separate statistics on customer base, can make one particular type of cus