<?php
add_filter( 'em_booking_email_messages', 'disable_pdf_tickets_for_category_18', 999, 2 );
add_filter( 'em_multiple_booking_email_messages', 'disable_pdf_tickets_for_category_18', 999, 2 );
function disable_pdf_tickets_for_category_18( $messages, $EM_Booking ) {
