This setting is specifically in regards to how other people will view the default information from your site's RSS output. The configuration options include:

• Feed description - description of your site, included in each feed.
• Number of items in each feed - options include 1 thru 10, 15, 20, 25, 30
• Feed content - global setting for the default display of content items in each feed:
  • Titles only
  • Titles plus teaser
  • Full text

When your configuration choices have been made, click on the Save configuration button to finish