Materials processed on the slip/invoice lines can also be selected by the Customer or Supplier code. By using this code in slip/invoice lines, users can easily access to the relevant material record. The material's customer/supplier code is entered by using the Customers/Suppliers option in the Attached Records menu of Materials browser. 
In order to save transaction using Customer/Supplier Code in sales slips and invoices, you can use Customer / Supplier Code option located under the Code Entry tab. The quantity field is used to specify the transaction quantity, and the code field is used to enter the Customer/Supplier code. The code and description of the relevant material are transferred to the slip lines.