To add a user-defined field, choose the Tools menu then select Customization Tools > User-Defined Fields – Management.
You can add new fields to most business objects, including business partner and item master data, and marketing documents.
Only authorized users can add user-defined fields. The general authorization is located in the authorizations window by navigating to Customization Tools > User-Defined Fields – Management.
User-defined fields are added to the respective database table for the object. They can be quickly identified in the database table, since they have the prefix “U_”.
User-defined fields are retained when you upgrade the system to a new release.