HTML5 and longdesc
The longdesc attribute, which is used to reference a page that contains a longer description of a complex image (such as a chart or graph), is currently not present in the HTML5 specification. It was dropped due to poor implementation by authors (it was often coded incorrectly or didn’t provide a true alternative to the complex image), poor browser support, and because it really only provided utility for some screen reader users. Unfortunately, there is not yet a suitable alternative attribute or functionality in HTML5 or ARIA for referencing a long description page. While longdesc will likely have continued support in browsers and screen readers for some time, it has long been recommended that for optimal usability and accessibility that authors provide a standard link to the long description page instead of or in addition to using longdesc.
I appreciate you taking to time to contribute That’s very helpful.