Default WordPress comments box is allowed style and other HTML like URL link, you can disable without install any plugins for HTML or URL links in your WordPress comments box using code below.
[php]
function plc_comment_post( $incoming_comment ) {
$incoming_comment[‘comment_content’] = htmlspecialchars($incoming_comment[‘comment_content’]);
$incoming_comment[‘comment_content’] = str_replace( "’", ‘'’, $incoming_comment[‘comment_content’] );
return( $incoming_comment );
}
function plc_comment_display( $comment_to_display ) {
$comment_to_display = str_replace( ‘'’, "’", $comment_to_display );
return $comment_to_display;
}
add_filter( ‘preprocess_comment’, ‘plc_comment_post’, ”, 1 );
add_filter( ‘comment_text’, ‘plc_comment_display’, ”, 1 );
add_filter( ‘comment_text_rss’, ‘plc_comment_display’, ”, 1 );
add_filter( ‘comment_excerpt’, ‘plc_comment_display’, ”, 1 );
remove_filter( ‘comment_text’, ‘make_clickable’, 9 );