If you like to listen to your favorite internet radio that does not appear on the iTunes Radio sidebar, you probably have a bunch of radio stations in your Library. A quick way of having them all in one playlist is to set up a Smart Playlist with this rule: Time -- is greater than -- some large number, say 10 hours.
iTunes recognize that "Continuous" is longer than any fixed time span, and so you'll have your radio stations conveniently located in one place.
Another way to organize radio would be to use the Sorting tab in the station's properties -- in many cases, information from the Info tab gets reverted to the station's default when starting playback.
Mac OS X Hints
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