January 2013 Standards Update
Updates on @longdesc and describedAt
by Geoff Freed
The WAI’s HTML5 accessibility task force continues to debate the merits of specifying @longdesc in an extension spec to accompany the full HTML5 recommendation. The current extension spec still awaits being moved forward to first public working draft (FPWD) status. A few outstanding objections from task force members remain to be addressed; once they are settled and the doc is moved to FPWD, @longdesc will be removed from the list of obsolete HTML5 attributes and elements. As mentioned in previous updates, NVDA now recognizes and announces the presence of @longdesc on images– JAWS has done so for a long time– and @longdesc is still part of HTML4, so image descriptions can still be delivered in HTML using this method. The bigger question of whether @longdesc will be part of HTML5 has yet to be resolved, although past agreement from most task force members indicates that the extension-spec route is generally acceptable.
Alternative methods of delivering hidden image descriptions are still being discussed, including ARIA-describedAt (unofficial first draft) and epub-describedAt (summary). James Craig at Apple has also created an example of how hidden iframes can be used to convey long descriptions using existing markup and just about any screen-reader/browser combination: see the explanation and demo.