W3C home > Mailing lists > Public > www-validator@w3.org > March 2001

RE: Code: 501 Protocol scheme 'javascript' is not supported

From: Thanasis Kinias <tkinias@asu.edu>
Date: Mon, 26 Mar 2001 16:38:38 -0700
To: "'shannonb@xilinx.com'" <shannonb@xilinx.com>
Cc: www-validator@w3.org
Message-id: <A021872EC2BDD411AB3600902746A055016047F7@mainex4.asu.edu>
Shannon Bristow wrote:

> I am getting an error message on links to javascript.  To include
> javascript in a page, such as opening a new window, is relatively
> common. Is this really not supported or am I doing something wrong?

Many people would consider using javascript: hrefs "doing something wrong."
AFAIK, the HTML specifications do not address what protocols are allowable
as the content of hrefs.  However, I'm not sure that these are valid URLs --
from RFC2396 [1]:

> The term "Uniform Resource Locator" (URL) refers to the subset of URI
> that identify resources via a representation of their primary access
> mechanism (e.g., their network "location")

Using javascript: as a "protocol" isn't addressing a resource, really; it's
frequently addressing an action to be taken.  That's not what a URL is
supposed to be.

The more important question if you're using javascript: hrefs, rather than
whether they're "legitimate" URIs, is whether they are accessible to your
target audience, and (if you are in the United States, Australia, or other
country with anti-discrimination laws regarding the handicapped) whether
they have the effect of discrimitating against handicapped users, putting
you afoul of the law.  The Web Content Accessibility Guidelines [2],
guideline 6, checkpoint 6.3 gives:

> Ensure that pages are usable when scripts, applets, or other 
> programmatic objects are turned off or not supported.  If 
> this is not possible, provide equivalent information on an 
> alternative accessible page. [Priority 1]

Unless you provide alternate, non-javascript links (via http:// URLs,
typically), your pages are inaccessible to those unable to use javascript,
which includes most blind users with aural browsers, or anyone else using
older software.  Opening new windows also violates checkpoint 10.1 [3]:

> Until user agents allow users to turn off spawned windows,  
> do not cause pop-ups or other windows  to appear and do not 
> change the current window without informing the user. [Priority 2]

On the Web, just because it's common practice, doesn't mean it's "right" in
technical or ethical terms; it also doesn't mean it's legal.


[1] <http://www.ietf.org/rfc/rfc2396.txt>
[2] <http://www.w3.org/TR/WCAG/#gl-new-technologies>
[3] <http://www.w3.org/TR/WCAG/#gl-interim-accessibility>

Thanasis Kinias
Information Dissemination Team, Information Technology
Arizona State University
Tempe, Ariz., U.S.A.

Qui nos rodunt confundantur
et cum iustis non scribantur.
Received on Monday, 26 March 2001 18:47:15 UTC

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