How to modify the source code to fix hAtom errors? There are different ways to modify your code. You could edit the single.php template file in your theme or childtheme, or any other files that control your blog article pages, and add in the extra class names into the correct spots. Alternatively, and I think that this is probably an easier modification for people who are unsure how to modify post templates, you can add the below code to your functions.php file of your WordPress childtheme. If you use a c

Source: Fix hAtom microformats – at least one field must be set for HatomEntry | David Tiong Web Consultancy