(13)The requirements in the margin rules of Japan for the calculation of initial margin are equivalent to the requirements set out in Regulation (EU) No 648/2012. In a similar manner to the standardised method for the calculation of the initial margin set out in Annex IV to Delegated Regulation (EU) 2016/2251, the margin rules of Japan allow for the use of a standardised model equivalent to the one laid out in the aforementioned annex. Alternatively, internal or third party models may be used to calculate the initial margin where those models contain certain specific parameters, including minimum confidence intervals and margin periods of risk and certain historical data, including stressed periods. Counterparties must notify the JFSA, METI or MAFF, as appropriate, of their intention to use those internal or third party models and must disclose any necessary assumptions, hypotheses and changes thereto.