Re: 'alt' was: SVGAccessibilityWG: has-been-clicked or a:visited

> > alt is used to describe an image.

alt is used to *replace* an image.  That's particularly significant
on commercial sites, because it is quite rare for an image to be
there for (just) its literal content, which is what a description will
give you.  Commercial site images tend to be for:

- layout (maybe no alt text);
- branding (may be impossible to convey this with just alt);
- to make an association with the product that cannot be objectively
  justified, so would be illegal if done in words.

Where there is no hidden sub-text, alt should be what you would
have put at that place in the page if images had not been possible,
in the first place.