XDocument.Save Method (Stream)
Assembly: System.Xml.Linq (in System.Xml.Linq.dll)
The serialized XML will be indented. All insignificant white space will be removed, and additional white space will be added so that the XML will be properly indented. The behavior of this method is that insignificant white space will not be preserved.
If you want to control white space, use the overload of Save that takes SaveOptions as a parameter. Use the DisableFormatting option to save unindented XML. This will cause the writer to write all white spaces exactly as represented in the XML tree.
Use OmitDuplicateNamespaces option if you want to remove duplicate namespace declarations.