description (string: url-encoded): This param lets you pass in a custom url-encoded string if you want to customize the description of a unique podcast feed. This is not necessary if your feed is derrived from a single category. Category only feed will automatically adopt the category description as their description.
This will return a podcast feed with the 60 most recent media items related to teacher 1 and category 1, with the custom description: "Sermons by Tom Pennington".
Remember you MUST pass this as a url-encoded string. Here is a free site where you can type out a string and url-encode it with the click of a button.