Thank you for the patches, but I do not think this is quite done.

1. "It is recommended that you always specify an encoding; you may use any encoding you like, but an argument of "utf-8" is the most common, avoid :exc:`UnicodeError` exceptions in case of unrepresentable text data."
The phrase after the comma is garbled. I think it means something like "It avoids :exc:`UnicodeError` exceptions for unrepresentable text data."

2. For Node.toprettyxml(indent="", newl="", encoding="")
I think 
"There's also an *encoding* argument, that behaves like the corresponding argument of :meth:`toxml`."
should simply say 
"The ``encoding`` argument behaves like the corresponding argument of :meth:`toxml`."

We already know there is one because it is there in the signature. I suspect saying so might date back to when there either was no signature or encoding was left out of it.