When deciding which XML features to bring to the .NET Compact Framework's XML architecture, the designers chose to focus on code footprint size and performance instead of implementing the full set of W3C XML standards. The following lists the features that the .NET Compact Framework designers chose not to support:
Document Type Definition Support
Even without these features the .NET Compact Framework provides robust, feature-rich support for manipulating XML data. Support for forward-only, noncached reading and writing is provided by XmlTextReader and XmlTextWriter, while the XmlDocument allows for the traversing and manipulating of XML data through a node tree data structure. ...