(23)In order to improve legal certainty, it should be clarified when the requirement to publish a supplement to the prospectus and the right of withdrawal end. Those provisions should be looked at separately. The obligation to supplement a prospectus should be terminated at the final closing of the offering period or the time when trading of such securities on a regulated market begins, whichever occurs later. On the other hand, the right to withdraw an acceptance should be applicable only where the prospectus relates to an offer of securities to the public and the new factor, mistake or inaccuracy arose before the final closing of the offer and the delivery of the securities. Hence, the right of withdrawal is linked to the timing of the new factor, mistake or inaccuracy that gives rise to a supplement, and assumes that that triggering event has occurred while the offer was open and before delivery of the securities.