In the process of studying the global state of our doctests, I noticed that the doctests in Doc/library/ctypes.rst use the following doctest directives: # doctest: +LINUX # doctest: +WINDOWS However, I'm not able to find evidence that these directives are implemented anywhere. Thus I get an error like the following when trying to parse the file using doctest: "ValueError: line 55 of the doctest for ctypes.rst has an invalid option: '+WINDOWS'" The reST file says this towards the top: "Note: The code samples in this tutorial use :mod:`doctest` to make sure that they actually work. Since some code samples behave differently under Linux, Windows, or Mac OS X, they contain doctest directives in comments."" The farthest back I was able to trace this paragraph was here from April 2006: http://hg.python.org/cpython/rev/0e0e315b4202 in which the docs seem to have been added from reST sources outside the repository (from ctypes 0.9.9.6 upstream -- see the parent changeset). I would like for our docs to be parseable by doctest without error. Possible options seem to include at least (1) changing these directives to normal code comments until we can support these directives in a meaningful way, and (2) calling doctest.register_optionflag() for these directives as no-ops as appropriate to make the errors go away. Does anyone have any thoughts on this? Thanks, --Chris