Breaking Backwards Compatibility is an Intolerable Cost

Breaking both compatibility with existing best practice (and documentation of the same), as well as requiring a wide range of tools, content, and authoring guidance to be updated in order to achieve compatibility with a replacement for longdesc - for something meant to solve the same problem, is an intolerable cost. It would be an illogical undue burden and unacceptable to authors and organizations that have already made investments in the use of longdesc in terms of tools, content and documentation. All other "solutions" introduce a non-backwards compatible change which negatively affects:

The vision of HTML5 was to extend the Web without breaking it; evolution rather then revolution.

Existing Tools

Longdesc is implemented in authoring tools, assistive technology, and user agents.

Not everyone can afford to throw away tools to get the newest model. For instance run of the mill content authors/web designers rarely can afford to throw away their WYSIWYG editor to get the newest model. They rely on existing tools to author and test long descriptions. It has been well established that WYSIWYG tools simplify authoring longdesc. An array of tools exists to author longdesc and to check that the longdesc works. Authors rely on tools to test long descriptions. Two browsers (Opera, iCab) natively support longdesc link testing (three if we count Home Page Reader which is currently still in use in Japan). longdesc has a growing arsenal of extensions, configurations, and plugins that are used for testing including Jim Thatcher's powerful long description favelet , which provides universal functionality of longdesc in browsers such as Chrome, FireFox, Internet Explorer, and Safari.

Longdesc-related features in existing authoring tools should continue to output valid content: both authors and users have perfectly reasonable expectations that longdesc will continue to be supported by existing tools, and will continue to have its current (i.e., intended) effect in existing content.

Existing Content

It has been substantially evidenced via the documentation of over two thousand real world examples of longdesc that authors do indeed use longdesc in practice to improve accessibility. This is a non-negligible number of example <img> elements that utilize longdesc in meaningful ways. All of the images in those examples would be significantly less accessible (some even totally inaccessible) without it. By using longdesc these real world examples provide programmatically determinable long descriptions of content in accordance with a target audience's needs. Example sites using longdesc include but are not limited to:

For an image that is fully accessible and compliant today to suddenly be flagged as non-compliant is counter to the backwards-compatibility and interoperability objectives of HTML5.

During the past year alone, numerous organizations such as the A11y Bugs Project, Aboriginal Affairs and Northern Development Canada, Alienor, Assisted Human Reproduction Canada, Axel Schäfer, SPD Abgeordneter im Deutschen Bundestag für Bochum, CSS Squirrel, Canada Virtual Museum of Valentines, Canadian Department of Justice, Canadian Space Agency, Correctional Service Canada, Department of Transportation (Taiwan), Cornell University, Courts Administration Service (Canada), Daegu Metropolitan Office of Education (South Korea), Office of the Superintendent of Financial Institutions Canada, Elections Canada, Environment Canada, Griffith University (Australia), Hipocampo, HTML Accessibility Task Force, HTML5 Multimedia, Immigration and Refugee Board of Canada, Kyungpook (South Korea), Marine National Park (Taiwan), Marden Neighbourhood Plan, Michigan State University, National Center on Birth Defects and Developmental Disabilities, National Institute of Standards and Technology (NIST), National Institute on Drug Abuse, Object Description, Office of the Commissioner of Review Tribunals, Ohlone College, University (South Korea), Oracle, Oriental Hospital of Daejeon University (South Korea), Panel on Responsible Conduct of Research (Canada), Paris Web, Parliament of Canada, Procréation assistée Canada, Public Safety Canada, Public Works and Government Services Canada, Rebuilding The Web, Social Security Online, Special Education Support Center (South Korea), Statistics Canada, Statistique Canada, Substance Abuse & Mental Health Services Administration, tech.burningbird, Transport Canada, Transportation Safety Board of Canada, Treasury Board of Canada Secretariat, Texas State Library, U.S. Department of Health & Human Services, and the University of Minnesota have used it in reports and publications.

Notably the two sister sites Statistics Canada and Statistique Canada began consistently using longdesc in "The Daily" publication. "The Daily" produces statistics on a business-day basis that help Canadians better understand their country, its population, resources, economy, society and culture. Please refer to Statistics Canada and Statistique Canada for detailed evidence.

On July 29, 2011 Suzanne Taylor and Ed McCoyd, Esq., of the Association of American Publishers attested:

We are using longdesc increasingly in our products.

Expecting authors to rewrite deployed content in order to support techniques that (a) do not work for authors or users, (b) are not programmatically determinable, (c) ignore aesthetics and other constraints, and/or (d) are simply cumbersome "hacks", is nonsensical and totally unrealistic: such attempts will serve only to infuriate and alienate both those authors and the accessibility community as a whole. Content owners should not have to re-author content, already being delivered to legacy devices as well as to today's leading-edge browsers and assistive technology, in order for it to be valid and accessible HTML5.

Existing Documentation

Obsoleting longdesc would result in mixed messages between existing documents and HTML5. Such messages can serve only to confuse. Those who encounter the array of books, online tutorials, guidelines, laws, policies and standards that have already recognized longdesc's importance to accessibility will expect longdesc to continue to function as described.

Materials such as these have a way of living on; they will not be obsoleted in the foreseeable future, and therefore neither must longdesc.

Reinstating Preserves Hard-Won Progress

Access for people with disabilities is essential. This does not mean that features should be made obsolete if not all users can fully make use of them but rather that mechanisms that have a foothold must be retained. As Bill Shackleton has stated,

...an essential flaw in the key reasoning, as I understand it, to remove longdesc is in assuming that because its past effectiveness has been limited, it is doing more harm than good. That is to say, that because of poor implementation - by user agents, by content authors, etc. - it should therefore be removed.

I respectfully disagree. Much accessibility work takes time and yes, some of that time includes the need for awareness and training. In my experience, progress in accessibility has rarely been consistent or even linear... And it is definitely not binary.

It progresses in fits and starts and even, unfortunately, backslides. That's why it's important, in this case as in others, to wedge in a backstop to preserve hard-won progress. Fortunately it is fundamental W3C policy that everyone be included (regardless of disability). This means that the burden of proof does not lay with the accessibility community to make the case for maintaining longdesc in the next version of HTML, but with those who wish to remove it.