A number of key features are only available to registered users. They include:

• Access to the full content of top-rated material (only teasers are available to anonymous users after the material has been posted for 45 days)
• The ability to search site content
• The ability to access reviews of books relevant to site material
• The ability to access key quotes relevant to site material
• The ability to access content from partner sites
• The ability to rate material
• The ability to post comments
• The ability to post new information and propose it for publication
• The ability to request email notification when selected content is added or updated