Offer conditionality allowing acquirer to set a minimum acceptance level, with MoU requiring rescission if unmet. Regulation 21A permits an acquirer or any person acting in concert to make an offer conditional on the level of acceptance, which may be less than twenty per cent subject to related regulatory provisos; where the public offer is pursuant to a Memorandum of Understanding, the Memorandum must state that if the desired level of acceptance is not received the acquirer shall not acquire any shares under the Memorandum and shall rescind the offer.