I have done some more tests.
I cleaned my testblog completely for all special characters and did some tests:
Read the feed in Firebird:
Add the feed in RSS Bandit:
Refresh feed '\Testblogg' failed with error: Unexpected HTTP httpResponse: NotFound
Add the feed in NewsGator:
Error: subscription could not be added. Please check the URL and try again.
Add the feed in Sharpreader:
Error reading URL: The remote server returned an error: (404) Not Found.
Testing the feed in Feedvalidator.org:
Server returned HTTP Error 404: Not Found
Adding the feed in Mozilla Tunderbird:
....then I add one post with one Norwegian character in the subject:
It stops working in Thunderbird and will not read in a browser.
So, the RSS-feed is actually quite useless in any cases. And, completely useless if you have a special character in the subject of a feed.
I have now added a norwegian character to one of the posts in this testblog, so right now it does not read at all...
This is the feed:
I have not done any localization of WordPress, and these are the feeds of my other blogs:
...does not work very well...
Suggestions are welcome!