spencejs

//Add Instructions to Featured Image Box
add_filter( 'admin_post_thumbnail_html', 'add_featured_image_html');

function add_featured_image_html( $html ) {

    return $html .= '<p>This is some sample text that can be displayed within the feature image box.</p>';

}

cliffordp

<?php

// From https://gist.github.com/cliffordp/74b66ceb1a15ce025e7f

// Send Event Tickets RSVP/purchase email to multiple recipients (e.g. site admin email or custom email)
// NOTE: sends to all recipients in single email (not CC or BCC, which would be preferable)
// @link: https://github.com/moderntribe/event-tickets/blob/release/122/src/Tribe/RSVP.php#L373
add_filter( 'tribe_rsvp_email_recipient', 'cliff_event_tickets_email_copy_to_admin', 30 );
function cliff_event_tickets_email_copy_to_admin( $to ) {
  $additional_recipients = array(