library.pdf, Section 25.4.3 Methods of RawTurtle/Turtle and
corresponding functions does not format the :param xxx: keyword
properly. The HTML version at http://docs.python.org/library/turtle.html
looks like

turtle.fd(distance)¶
    Parameters:	

        * distancea number (integer or float)

The formatting in HTML version is 100% correct, since it misses a space
between 'distance' and 'a', but at least is readable. The screenshot of
the PDF is not really readble. There is also the space missing between
the parameter and its description.