This section and its subsections are informative (non-normative).
The specification of WebCGM applies concurrently with the internationalization and accessibility recommendations. However, as described in [Essential Components of Web Accessibility], several components such as authoring tools, media viewers and developers, have to work together to improve Web accessibility.
For example, graphical text is ideally stored as Unicode text strings within the WebCGM metafile, but to handle cases where graphical text images are actually the result of other vector (e.g. stroking) or raster (e.g., bitmaps) graphics in the metafile, WebCGM has the attribute 'content' on the para and subpara objects, that gives the text-string equivalent of the rendered graphical text.
Features that are in the binary metafile itself will, unlike clear-text formats such as HTML, XML, and SVG, require the cooperation and intervention of the WebCGM authoring tools and viewers. Therefore, the discussions in the following sections are recommendations for WebCGM authoring tools, viewers and developers.
By default, WebCGM viewers allow the user to move the content focus to enabled elements (i.e. element whose 'visibility' attribute is 'on') only. For example, objects which are not visible do not display tooltips (the 'screentip' APS attribute), may not be highlighted without making them visible, and may not be navigated to via the DOM or picture behaviors. It meets a requirement of [UAAG10] CheckPoint 9.3.
In addition, WebCGM viewers can offer a mode where, at user option, the 'visibility' attribute is ignored, for accessibility or debugging support.