RE: ALT-attribute usage

Somewhere in here I think we need to differentiate the nature of ALT and LONGDESC.

We sometimes say things like

ALT = Short Description
LONGDESC = Long Description

I think ALT is a little different.  It is supposed to describe the FUNCTION.  While LongDesc is more of a description of the appearance.

Maybe we should say

ALT = short description of the FUNCTION 
LONGDESC = (long) description of the IMAGE 

For example a bullet shaped like an arrow would have alt text  "bullet"   not "yellow arrow pointing right"

An Image button for search would say  "search"   Not  "Magnifying Glass with Search on it"  or "magnifying glass"


What you think?   How do we convey this idea.   Even more important in light of discussions about tool tips etc.

Gregg