Texts in the SD module carry and share information, such as shipping instructions, through master data and transactional data. You can configure the system to propose the text from the master data or within a document and carry it across the supply chain process. The system then can copy the text to subsequent documents, so you don’t need to enter the information again. You also can use the text as an instruction for subsequent processes — for example, a note in the delivery document that specifies pick-up instructions.
For instance, you could record customer instructions for receiving the goods. You also could use texts when you have an agreement that is about to expire and you want to send a note with the document that accompanies the goods you send the customer. Another example would be if your customer would like to receive products in a particular sequence. In this case, you could include this information in the shipping instructions, which would notify the warehouse folks of the request before they ship the product.
the t.code is VOTXN to setup text determination. here you can select it for sales document header item, delivery and billing header item details. Also you can do it customer texts. you can configure the text procedure which contain several text ids which during the sales order can be used to maintain additional information.