[whatwg] longdesc [was: A new attribute for <video> and low-power devices]

[Jim Jewett]

> In the ~0.1% of images where
> longdesc= is used, it's misused literally over 99% of the time:

> http://blog.whatwg.org/the-longdesc-lottery

Responding for the archive; that blog bost keeps getting cited, but it
isn't up to Mark's usual standards.  longdesc is not a success story,
but neither is it the miserable failure suggested by those numbers.

The 99.9% unused is (or at least was) probably close to correct, and
is a good thing.  I just checked the front page of CNN, where there
are 137 images, of which at most one would benefit from a longdesc --
and even that one is pretty questionable.

The 99% misused is at best debatable.  I'm pretty sure that using a
longer human-readable description instead of an URL was once
(admittedly long ago) recommended.  It worked at least as well with
the browsers I tested with at the time.  Blanks should be treated the
same way as blank alts -- an explicit statement that this image does
not need a long description.  URLs which are redundant to something
else in the area are actually a good thing, since that "something"
isn't standardized. (aria-described-by should offer a better solution
going forward.)

http://wiki.whatwg.org/wiki/Longdesc_usage makes it clear that useful
(if not pedantically correct) usage is much greater than 1% of the
actual usage.  Not as high as it should be, certainly, but still
better than, say, the percentage of tables which represent data rather
than layout.

-jJ