drupal8-content-editing.md

@@ -84,6 +84,12 @@ And also:
 * `top50p`
 * `top30p`
 
+# Body classes
+
+The [custom_body_class]() module makes it possible to add a custom CSS class name in the `body` tag. This is sometimes necessary for backwards compatibility, or just to more easily theme a specific page.
+
+* `page-title-center`
+
 ## Drupal7 CSS documentation
 
 https://civicrm.org/node/6286