But just one thing I don't understand ...
Whenever I add an image now, it always has a longdesc attribute and return anchor, like this ..
<img class="alignright size-full wp-image-100" alt="" src="http://[MY-DOMAIN]/wp-content/uploads/2014/04/[IMAGE-NAME].jpg" width="160" height="160" longdesc="http://[MY-DOMAIN]?longdesc=100&referrer=113" /> <a id="longdesc-return-100"></a>
I cannot see how to turn off this unwanted behaviour.
Most of my images are small and purely ornamental. None of them have title, alt text, description or caption — because they are not needed.
I'm grateful for the opportunity to add an appropriate longdesc, but right now all images have a link to an empty description, unless I edit the image tag manually.
Have I done something wrong? Have I missed an obvious instruction (very possible - my vision is deteriorating week by week).