If the portlet instance will be host to numerous RSS feeds, you might want to create categories to group them. Categories typically are displayed as yellow folder icons that can be expanded or collapsed to show or hide the feeds they contain.
You can also create a category as part of the process of adding a feed, as described in Subscribing to a feed.
To create a category:
1. Navigate to the appropriate portlet instance and click Add Category.
2. In the form displayed, enter a name for the category.
3. Click Save.