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Acronym/Abbreviation best practice

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From: Jared Smith
Date: Mar 12, 2009 10:35AM

I'm struggling a bit with how best to expand acronyms and
abbreviations. Any insight you can provide would be valuable.

Which of the following do you believe is the best approach:

1. Expand only the first occurrence of the acronym in text -
"Assistive Technology (A.T.)" or "A.T. (Assistive Technology)"
This approach provides the expansion visually for all users. But if a
screen reader user jumps to a later instance of the acronym, they do
not get the expansion.

2. Expand only the first occurrence of the acronym using <acronym>
only - <acronym title="Assistive Technology">A.T.</acronym>
This approach provides the expansion, but as with #1 - only does so on
the first instance only.

3. Both 1 and 2 for only the first instance - Assistive Technology
(<acronym title="Assistive Technology">A.T.</acronym>)
This one seems redundant to me. A screen reader with
acronyms/abbreviations set to read would hear "Assistive Technology
Assistive Technology".

4. Expand all instances of the acronym using <acronym title="Assistive
Technology">.
This would always provide the expansion, but this could become VERY
tiresome - especially for long expansions (e.g., XHTML) and would
essentially negate the purpose of using the acronym.

5. Fully expand the first instance using <acronym title="Assistive
Technology">A.T.</acronym> then simply us <acronym>A.T.</acronym> for
all other instances.
Screen readers do nothing with acronyms if there is not a title
attribute, so only the first instance provides the needed expansion.
#5 still has the same problem as #3 if you also expand the first
instance in text.


So, which do you think is best? Or do you recommend some combination
of the above?

Of note is that WCAG 2.0 SC 1.3.4 allows #1 OR #4, but does not really
provide for any other possibilities -
http://www.w3.org/WAI/WCAG20/quickref/#qr-meaning-located

I would think that #5 would be the best approach, but only if screen
readers fully expanded the acronym at the first instance it is
encountered (which may not necessarily be the first one in the code
that has the full expansion with the title attribute). But screen
readers don't currently behave this way, so what do we do?

Jared Smith
WebAIM

PS - Also of interest is the fact that <acronym> is not part of the
HTML 5 spec. <abbr> would be used for all things acronymish -
http://dev.w3.org/html5/spec/Overview.html#the-abbr-element Also note
the <dfn> element which is intended to be used with <abbr> -
http://dev.w3.org/html5/spec/Overview.html#the-dfn-element