replace comma tags in answers in visible (but not hidden) text

gistfile1.txt

add_filter ( 'the_content', 'who_cares_about_an_oxford_comma', 11 );
 
function who_cares_about_an_oxford_comma ( $content ) {
  $base = '#(<span.*)\{comma}(.*</span>)#';
  $replace = '$1,$2';
  $new_content = "";
  while (($new_content = preg_replace( $base, $replace, $content )) != $content) {
	$content = $new_content;
  }
  return $new_content;
}