Here you can choose rss feeds from site categories. The feeds will present either decriptions or downloads of Nzb files.
Most Nzb clients which support Nzb rss feeds will appreciate the full URL, with download link and your user token.
The feeds include additional attributes to help provide better filtering in your Nzb client, such as size, group and categorisation. If you want to chain multiple categories together or do more advanced searching, use the api, which returns its data in an rss compatible format.