Debugging Drupal 7 Templates
Drupal 7.33 introduced the ability to add helpful comments to your source code for better debugging of your templates. This is similar to how it now works in Drupal 8 with inspecting your Twig templates. I hadn’t known about this feature until quite recently, and since I still maintain some Drupal 7 sites, this feature is incredibly helpful when trying to debug a template.
Add this line to your settings.local.php and then clear cache.
$conf['theme_debug'] = TRUE;
Simple, I know, but after adding this, open you your inspector and give it a hard reload to see all the commented helpers inserted. The link below provides a much better detail of this setting.
https://www.drupal.org/node/1089656 suggestions”) (Template suggestions)