register_extended_post_type('contact',
  [
    'menu_icon' => 'dashicons-media-text',
    'supports' => [ 'page-attributes', 'title', 'slug']
  ],
  [
    # Override the base names used for labels:
    'singular' => 'contact',
    'plural'   => 'Contacts',
    'slug'     => 'contact'
  ]
);

register_extended_taxonomy( 'group', 'contact', array(), array(
    'plural' => 'Groups',
    'slug'   => 'group'
    )
);

register_extended_taxonomy( 'region', 'contact', array(), array(
        'plural' => 'Regions',
        'slug'   => 'region'
    )
);