Possible Duplicate:
Fail of markdown parser detected if _ are used in naked url
Link with double-underscored word in URL renders incorrectly
I'm posting this video as part of the solution to this question, but the problem is that the YouTube URL parser chokes on the link.
http://www.youtube.com/watch?v=_-G520ACFUo
The URL has both a dash and underscore in it and that seems to break the parser.
http://youtu.be/_-G520ACFUo
The short version does not work either.
%5f
seems to be a workaround. For reference, here's the answer, and here's the last borked revision. Oh, and that particular video has embedding disabled, anyway.