[Inkscape-user] text-decoration and overline-position / overline-thickness

Folks; SVG 1.1 provides the @overline-position and @overline-thickness attributes (http://www.w3.org/TR/SVG/fonts.html#FontDescriptions) and @text-decoration="overline" (http://www.w3.org/TR/SVG/text.html#TextDecorationProperties). I can't figure out how to apply such text decorations (in particular, overline) to text in Inkscape, and I'm finding that some rendering engines don't know how to display them. As a test, if one takes opens the file @ http://www.w3.org/TR/SVG11/images/text/textdecoration01.svg in Firefox 3.5, the text decorations aren't applied. They are rendered in Safari 4 and Chrome 2. So what's the *real* status of text decorations in SVG? Thanks in advance for your help, Bob