// Replace the first underline with a colon.
$tag_name = str_replace('og_', 'og:', $tag_name);
$tag_name = str_replace('article_', 'article:', $tag_name);
// Replace the first underline with a colon.
$tag_name = str_replace('og_', 'og:', $tag_name);
$tag_name = str_replace('article_', 'article:', $tag_name);
// Some tags have an additional underline that turns into a colon.
$tag_name = str_replace('og:image_', 'og:image:', $tag_name);
// Some tags have an additional underline that turns into a colon.
$tag_name = str_replace('og:image_', 'og:image:', $tag_name);