Analysis of Podcast RSS feeds

I have found a few of challengies for making Podcast as LMS content package.

1. The control of display is on the client side.
2. Supported content types (MIME-type applications) is depending on the client systems.
3. The access control to resource, items. (not too much to the Feed)

I am working on now is to distiguish Podcast RSS attributes to Descriptive and Publishing; whereas, Descriptive information is basically the information on items and Publishing information is the elements of display and access, i.e. MIME indicator and authentication. The goal it to to do the authentication on the item level, but it will be application specific - no a standard method and that ruins the purpose of using RSS for standerizing content distribution. I am going to talk to Brent this afternoon who I am writing a paper on this project now ...