Section III - Feed parsing
IE7 supports the following feed formats: RSS 2.0 (0.91 and 0.92 included), Atom 1.0, and RSS 1.0. Section II explains the detection of these feed formats. Once it is detected properly, the feed is passed to the RSS Platform for sanitization and normalization. After this process, the IE feed reading view displays the feed for the user to read.
Feeds that reference a DTD are not supported by the RSS Platform. A DTD is used to help XML parsers with validation of the document. However, DTD validation is a potential source of security issues for XML parsers, and validation is not required for feeds to work correctly in aggregators. To read more about potential security issues with DTDs, please read this MSDN article.
To limit the impact that feeds with DTDs can have on a user’s computer, the RSS Platform’s parser rejects all feeds that contain references to DTDs and IE7 displays an error instead of showing the feed reading view. To enable the feed to be supported in the RSS Platform and viewable in IE7, the reference to the DTD needs to be removed.
Example of a feed with a DTD reference (not supported):
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rss SYSTEM "http://my.netscape.com/publish/formats/rss-0.91.dtd">
<rss>
Feed with no DTD reference:
<?xml version="1.0" encoding="UTF-8"?>
<rss>
By removing the DTD reference, the feed can be processed by the RSS Platform and displayed to the user in the feed reading view.