Rejection Reason Mandatory

Hi All,

Can we use HREJ or RREJ for Shopping cart or Purchase Order in Text Schema definition or they are only for confirmation and invoices? if yes, what else I need to do? what is the concept of implementing different kind of notes.

- SAP Implementation Guide

           - SAP Supplier Relationship Management

             - SRM Server

               - Cross-Application Basic Settings

                 - Text Schema

                   - Define Text Schema

I need to make Rejection reason mandatory for shopping cart and Purchase Order.

Is there any other way except implementing DOC_CHECK badi?