ElkArte 1.1.9 added support for structured meta data (features -> general in the ACP).  This will produce 
Open Graph and 
Schema.org data for various pages of your site.  This data is used by search engines and when a page is shared on a social media site and may help with SEO
To use the new data, which is available in 
$context,  you need to add a new calls in your 
index.template.php file.
First add the following in the same area where the template is outputting 
<meta style tags (robots, description, viewport) which is up in the page top section. 
	// If we have any Open Graph data, here is where is inserted.
	if (!empty($context['open_graph']))
	{
		echo '
	' .implode("\n\t", $context['open_graph']);
	}
Next in the 
template_html_below() function, after the line 
theme()->template_javascript(true); add the following:
	// Schema microdata about the organization?
	if (!empty($context['smd_site']))
	{
		echo '
	<script type="application/ld+json">
	', json_encode($context['smd_site'], JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), '
	</script>';
	}
	// Schema microdata about the post?
	if (!empty($context['smd_article']))
	{
		echo '
	<script type="application/ld+json">
	', json_encode($context['smd_article'], JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), '
	</script>';
	}
This will output the data at the end of the page.