Anton Litvinenko

add_filter( 'nav_menu_link_attributes', 'wpse121123_contact_menu_atts', 10, 3 );
function wpse121123_contact_menu_atts( $atts, $item, $args ) {
  // ID айтема в меню
  $menu_target = 123;

  if ( $item->ID == $menu_target ) {
    $atts['rel'] = 'nofollow';
  }
  return $atts;
}

var old = 0;
window.addEventListener("scroll", function() {
  let now = Math.floor(window.pageYOffset / 500);
  if ( now > old ) {
    console.log("Очередные 500", now);
    old = now;
  }
}, false);

const phones = Array.from(document.querySelectorAll('.change-phone'));
phones.forEach(phoneElem => {
  if (phoneElem.tagName === 'A') {
     // ...
  }
});