References

[PythonIssue3080]

see http://bugs.python.org/issue3080 The work seems finished with Python 3.3.

[HTML4.01Appendix_B2]

see http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.2

[HTML5URL]

see http://www.w3.org/TR/html5/infrastructure.html#urls . But the specification seems to request the encoding of the caller HTML should be utf-8 or utf-16.