Inclusion of SEO-related content in the header using structured Microdata
You can use Drupal hooks and functions like


hook_preprocess_html - Get and set metadata here
drupal_add_html_head - add element to HTML head


You could also call drupal_add_html_head from other API hooks such as hook_node_view, hook_ctools_render_alter, hook_init etc..

e.g:

/**
 * Implements hook_preprocess_html
 */
function mytheme_preprocess_html(&amp;$vars) {

  $content = drupal_get_title() ? drupal_get_title() : variable_get('site_name', 'Drupal');
  // Add open graph title to head
  $element = array(
    '#tag' =&gt; 'meta', 
    '#attributes' =&gt; array(
      'property' =&gt; 'og:title', 
      'content' =&gt; strip_tags($content) 
    ) 
  );

  drupal_add_html_head($element, 'fb_social_open_graph_title');

}