Although C# supports XML documentation (see Chapter 38), C# doesn’t provide any specific language support for using XML.
That’s okay, however, because the CLR provides extensive support for XML. Some areas of interest are the System.Data.Xml and System.Xml namespaces.
Source: Gunnerson Eric, Wienholt Nick (2005), A Programmer’s Introduction to C# 2.0, Apress; 3rd edition.