Use of transformations is of the highest importance when creating feeds, as all syndication web parts render the feeds using them. They need to be set in the Transformation property of each feed web part.
All document types in Kentico CMS have the RSSItem and AtomItem transformations. When you create a new document type, these transformations are created for it automatically.
The default RSS, Atom and XML transformations can also be generated when editing or creating transformations of a document type or a custom table. To do this, you only need to select the required format from the Code drop-down list and click the Generate default transformation button.
RSS transformations document type
Other feed transformations are found in a special document type called RSS transformations (CMS.RSSTransformations). This is a special document type used just to store transformations for Kentico CMS objects. Transformations for blog comments, board messages, forum posts, media library files and products are contained in the document type.