How to exclude certain url (RSS feed) from authentication?

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Hello, I have a private Askbot forum. There's a demand to use RSS feed, but since the site is private, it requires username password in order to access the RSS url, which is http://mysite.com/feeds/rss/?

I also tried to use the following scheme http://username:password@mysite.com/feeds/rss/? but it seems that the code doesn't support.

So my thought is to exclude the RSS urls entirely from authentication ( I understand the risk but it's OK). What's is the correct way to do this?

Many thanks,