A Main Specified Charge payable by Parties in relation to each month, there will be an Additional BM Unit Monthly Charge, for each Supplier BM Unit for which a Supplier is Lead Party for all or any part of that month, and which is not charged for under paragraph (g) , at an initial charge rate of £100 per month; has the meaning given to that term in paragraph 3.1 of Annex D-3;