On Tuesday, March 29, 2005, at 11:00 PM, Mark Nottingham wrote:
Of course, given that RSS has separate change controllers, it might be argued that it would be better to have different ones, but I'm not yet convinced; generally, you've got one app that can handle all of the formats; there's no meaningful difference between them.
But of course web browsers can handle GIF, JPEG, HTML,... Is the fact that RSS readers can handle both 1.X and 2.X feeds a result of lack of meaningful difference, or a result of user requirements to support both formats in one app? Not all RSS processors support both. Certainly the fact that there are major similarities makes it much easier to support both.
If we do go for a separate subtype for each, it might be good to do something to ensure that they're unambiguous. For example, "application/rss+xml" wouldn't do much to help a person recognize that it applied to one and not the other. "application/rss2+xml" makes that clear, but would become confusing if a hypothetical RSS 3.0 were released based on 2.X and a new MIME type were not registered for the new version.
...of course, contemplating using the same type for 2.X on 3.X might be an argument for using the same one for 1.X and 2.X. How similar would 2.X and 3.X need to be to justify using the same MIME type? This isn't a question I've pondered or heard discussion of enough to comment further.
