因為安全理由，所以wordpress 內建只有常見的協定的schema 才會被允許，不常見的協定會被消除，變成空白的，套用為預設的協定，就變成 https 了，所以如果你的網站的超連結想要提供以下的schema:
magnet, skype, line, sms, comgooglemaps, comgooglemapsurl, comgooglemaps-x-callback
可以修改 wordpress theme 裡的 function.php, 加入下面的程式碼：
function custom_add_more_protocols( $protocols ){
$protocols[] = 'line';
return $protocols;
}
add_filter( 'kses_allowed_protocols' , 'custom_add_more_protocols' );
相關文章
Browse: Home / Reference / Functions / esc_url()
https://developer.wordpress.org/reference/functions/esc_url/
Description
A number of characters are removed from the URL. If the URL is for displaying (the default behaviour) ampersands are also replaced. The ‘clean_url’ filter is applied to the returned cleaned URL.