Assembly: Microsoft.Office.Interop.Word (in microsoft.office.interop.word.dll)
You can access the Schema Library from within Microsoft Word from the XML Schema tab in the Templates and Add-ins dialog box. The Schema Library represents schemas installed on a user's machine that a user has applied to a Word document or that a user has explicitly added to the Schema Library by using the Schema Library dialog box.
Use the Item property of the XMLNamespaces collection to return an individual XMLNameSpace object. The index value of the Item property can be either an Integer, which indicates the position of the schema in the Schema Library, or a String, which represents the name of the schema as returned using the URI property (the TargetNamespace setting defined in the schema).