These values describe the position of one node relative to another, with respect to document order.
public enum XmlNodeOrder { Before = 0, After = 1, Same = 2, Unknown = 3 }
System.Object System.ValueType System.Enum(System.IComparable, System.IFormattable, System.IConvertible) XmlNodeOrder
System.Xml.XPath.XPathNavigator.ComparePosition( )