My understanding is, that custom post types can share tags with the posts also.
I have created tags and applied them to a blog post and a custom post type.
Yet when I click on a tag it only returns blog posts.
I have this line in my register post type:
'taxonomies' => array('post_tag')
But I also have this outside of the function
register_taxonomy_for_object_type('post_tag', 'projects');
Are they doing the same thing? Also why will it not return custom posts with that tag?