This property, along with DocTypeName, SystemId, and InternalSubset, provides all the document type declaration information. It is used to find and load the required DTD information so that you get all the default attributes and entities defined in the DTD.
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.