Elegant way to signify inheritance and relationship between posts

Using the Posts 2 Posts Module which is still being developed just no support is being offered except through the git fork. How to use it.

function my_connection_types() {
    p2p_register_connection_type( array(
        'name' => 'posts_to_pages',
        'from' => 'post_type_1',
        'to' => 'post_type_2',
        'cardinality' => 'one-to-many'
    ) );
}
add_action( 'p2p_init', 'my_connection_types' );

The above example will create a 1 to many relationship a post from post type 1 is in a relationship with many posts from post_type_2. Change carnality where needed. You will then have a metabox in your posts to add the relationships.

<?php
// Find connected pages
$connected = new WP_Query( array(
  'connected_type' => 'posts_to_pages',
  'connected_items' => get_queried_object(),
  'nopaging' => true,
) );

// Display connected pages
if ( $connected->have_posts() ) :
?>
<h3>Related pages:</h3>
<ul>
<?php while ( $connected->have_posts() ) : $connected->the_post(); ?>
    <li><a href="https://wordpress.stackexchange.com/questions/167597/<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
<?php endwhile; ?>
</ul>

<?php 
// Prevent weirdness
wp_reset_postdata();

endif;
?>

The above snippet if run on a single.php template will show the pages that the current post is connected with.