(14)The requirements in the CFTC Regulations for the calculation of initial margin are equivalent to the requirements set out in Regulation (EU) No 648/2012. Like Annex IV to Delegated Regulation (EU) 2016/2251, the CFTC Regulations allow the use of a standardised model. Alternatively, internal or third party models may be used for that calculation where those models contain certain specific parameters, including minimum confidence intervals and margin periods of risk, and certain historical data, including stressed periods. Those models must be approved by the CFTC or a registered futures association.