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Re: WCAG

for

From: Jared Smith
Date: Mar 2, 2010 1:54PM

On Tue, Mar 2, 2010 at 12:34 PM, Geof Collis < <EMAIL REMOVED> > wrote:
> I think I'll go with it as it sounds correct to me. I've always
> understood that 150 characters was the max

You're missing the point entirely. There is no max!!! Setting any
value to alternative text length will be entirely arbitrary. It would
be like saying any book of fiction over 150 pages is automatically a
novel and everything less is a short story. Absurd!

Alternative text should convey the content and function of an image,
and do so accurately and succinctly. Some images necessitate very long
alternative text. Most require a word or two. I think 100 characters
is a good threshold at which one should determine whether the
alternative for an image can adequately be conveyed through the alt
attribute. In some cases, this will be perfectly appropriate - maybe
even at 1000 or even 10000 characters (especially for images that
present lots of text). But in most cases, the fact that the alt value
is naturally becoming lengthy is an indication that the alternative
might be better presented in some other way, such as in adjacent text
or another page via link and (optionally) the longdesc attribute.

Jared