For SVG "none, see comment." does not help as the comment does not clarify what is supposed to happen. I think the correct answer here is that SVG only works if you use the proper extension and it would be worthy to point that out crystal clear.
Also, following the definition of file-extension _none_ of the entries in the table would be matched. I.e. file-extension requires a leading dot. -- Anne van Kesteren http://annevankesteren.nl/
