Because Ch is a superset of C with classes in C++. With Chlibxml2 Package for libxml2 Gnome XML C parser, functions and member functions in the libxml2 can be used directly in Ch. The documents for Chlibxml2 Package are exactly the same as documents provided by libxml2 Gnome XML C parser. Below is the original documents from libxml2 Gnome XML C parser.