Potential future exposure for options

According to Mark-to-Market method set out in Article 274 Regulation (EU) No 575/2013 (CRR), institutions should calculate potential future exposure and, as we understand, for options delta equivalent might be used as it is applied for Position risk? In case of OTC-options should institution have permission by the competent authorities for using institution's own delta model?

For the purpose of market risk capital requirements, options are treated according to articles 329, 352, 358(3), i.e. as if they were positions equal in value to the amount of the underlying instrument to which the option refers, multiplied by its delta. For OTC-options, or where delta is not available from the exchange concerned, the institution may calculate delta itself using an appropriate model, subject to permission by the competent authorities. However, for the purpose of counterparty credit risk capital requirements, no special treatment for options is explicitly stated in CRR. Institution calculating exposure value of derivatives according to Mark-to-Market method set out in article 274, shall calculate the potential future exposure of option as its notional amount multiplied by appropriate percentage from Table 1 of article 274 CRR. Our question concerns provisions set out in article 273 (8) CRR, stating that: "For the methods set out in Sections 3 and 4, the institution shall adopt a consistent methodology for determining the notional amount for different product types, and shall ensure that the notional amount to be taken into account provides an appropriate measure of the risk inherent in the contract". Is it correct to assume, that "methodology for determining the notional amount" of options should be consistent with the approach for market risk cap.req. purposes, i.e. delta equivalent should be taken into account when calculating potential future exposure of the option? If the above is correct, is the institution permitted to calculate delta itself for OTC-options using an appropriate model? Is permission by the competent authorities for using the model required?