diff --git a/booking.regn_form.inc b/booking.regn_form.inc
index 3a6b63d..7dca1b4 100644
--- a/booking.regn_form.inc
+++ b/booking.regn_form.inc
@@ -598,7 +598,7 @@ function booking_form($node, &$form_state, $inserting = FALSE)
     $form['emergency']['booking_medicare'] = array(
       '#type' => 'textfield',
       '#title' => t('Your Medicare Number'),
-      '#description' => t('Enter only the numbers at the top of the card (leave out the Individual Reference Number next to your name).'),
+      '#description' => t('Enter only the numbers at the top of the card (leave out the Individual Reference Number next to your name). Australian attendees must complete this field.'),
       '#maxlength' => 15,
       '#size' => 15,
       '#required' => FALSE,