I'm surprised I can't find the answer to this online.
I'm currently creating a custom header for my drupal site, so I've created a custom_header region in the .info and a region--custom-header.tpl.php file. Inside the region, I need to add another region.
I've tried to print the other region inside the header region, but nothing is showing up.
Good practise or not aside, how can I do this?