http://www.w3.org/mid/B6CB855C5769484F862F4FB2CCFA50F402D545A7@VHAISHMSGJ2.vha.med.va.gov

The Area Element

It states that if an area does not have an href then it cannot be
selected and thus does not require an alt attribute.  It is unclear how
that would comply with other requirements for alternative text on
images.  For example, imagine the areas in an image map represent rooms
in a house, but only the kitchen, living room and bedroom can be
selected, but there are also a bathroom, a dining room, and a library
represented in the image, which are not presently active.  Not providing
text representations of those rooms would be withholding information
from a user who does not have access to the image.  This would be
especially true if links from areas are dynamically generated.  It would
seem that having an area's text representation appear and disappear,
could be more disconcerting than having it always present, but with
appropriate indicators of whether it is an active link or an inactive
graphic.  Inactive areas could be kept out of the tab order though.
Also, a means would have to be provided for areas with empty alt
attributes from being placed in the tab order.  


[split out from bug 13590]