title: My Wordpress taxonomy should be required
body: <p>I have created a custom taxonomy and it works great, but i can't find a way to make it required in the dashboard.. Is there any way ?</p>
  
  <p>This is the code of the taxonomy :</p>
  
  <pre><code>  function create_extra_cat_guidlines() {
         register_taxonomy(
        'cat',
        'pr_guidelines',
         array(
          'label' =&gt; __( 'Category' ),
          'rewrite' =&gt; array( 'slug' =&gt; 'cat' ),
          'hierarchical' =&gt; true
        )
        );
    }
  </code></pre>
  
  <p>Thanks in advance !</p>