public abstract class XmlSchemaObject {
// Protected Constructors
   protected XmlSchemaObject( );  
// Public Instance Properties
   public int LineNumber{set; get; } 
   public int LinePosition{set; get; } 
   public XmlSerializerNamespaces Namespaces{set; get; } 
   public string SourceUri{set; get; } 
}

This abstract type is the base for all of the types that represent XML Schema elements. Its LineNumber and LinePosition properties provide information about the location of the element within the XML Schema document, and its SourceUri property provides information about the location of the source document itself. Although all the XML Schema types extend XmlSchemaObject, only XmlSchema and the three documentation types XmlSchemaAnnotation, XmlSchemaDocumentation, and XmlSchemaAppInfo do so directly; the rest extend the intermediate base types XmlSchemaAnnotated or XmlSchemaExternal.