1Jun/070
The skinny on OPML
OPML, or Outline Processor Markup Language, is a XML specification for defining outlines. Great. The spec is open by design, so you can outline just about anything that can be, uh, outlined. Most commonly, OPML is used to define playlists, for example a MP3 playlist or a list of podcast subscriptions.
Awesome! But one catch. Since OPML is both 1. Young and 2. Vaugue, how it is actually used in the dog-eat-dog real world of the internet differs from client to client, and website to website. Here are some things I found out:
When outlining podcasts, the url is often stored in these attributes:
<outline text="The+Onion+Radio+News" url="http://www.theonion.com/content/feeds/radionews" type="link" count="380" />
<outline text="The+Onion+Radio+News" xmlUrl="http://www.theonion.com/content/feeds/radionews" type="link" count="380" />
(iTunes style)
<outline text="The+Onion+Radio+News" xmlURL="http://www.theonion.com/content/feeds/radionews" type="link" count="380" />
(Digg style)
Additionally, the can be nested. One level nested is fairly common, but more than that seems rare.
