This may be because your first preference was for a competitive course with limited places and a large volume of applicants.
If you received an offer for a lower preference but would like to still be considered for your first preference in the second round of offers, allowing your offer to lapse will allow your application to be considered for the second round of offers.
If Curtin is unable to offer you your first preference in the second round of offers, your original offer will remain valid.
If you did not receive an offer during the main round of offers, you may wait until second round of offers to be considered for your first preference again. However, it is recommended that you include a non-competitive course in your list of preferences that is a suitable back-up course or alternative pathways.