oh, of course. The document should definitely say "don't bother to put in a description if there's no useful information to convey." Although that being said, technologically we actually don't have a way to have blank alt text. The way the software is functioning right now, it looks for something in the description field, and falls back to the keyword field if the description field is blank, and the description field will always be populated. (Even if it is your default icon, and you haven't set a keyword for it, the system gives it a placeholder keyword.)

Do you think it's important to open an enhancement request that would give people a checkbox for "don't bother providing alternative text for this userpic?" I feel like the only people who would actually use that checkbox would be the kind of people who pay enough attention to their userpics that they would always want alternative text.