Drupal's default RSS feed is bizarrely difficult to tame. There are a few issues with it, but the biggest one is the fact that each item's description has a link to the author's user profile appended to it in such a way that it can't be removed by any normal means—since user profile pages are not public for the vast majority of Drupal sites I build, this means there's effectively a link to a 403 error page in each RSS item.
Determining which Drupal regions have content seems like a reasonably straightforward task, but, as evidenced by this 12+ year old, six-digit node ID issue, it is not. In the course of building a base theme for future Drupal projects I decided it was worth the time to see how well I could work around the problems referenced in that issue in order to get accurate region content flagging working.
Drupal's core “Manage display” functionality provides the option to link images to content, which is handy for, e.g., teasers. If the link contains nothing but an image, however, some accessibility checkers will (rightly) flag these links because there's no textual information indicating where they're going. One solution is to add a
title attribute to the link.