EBU Single Rulebook Q&A 5 February 2019 2019_4517 Transactions in the banking book where no strike is available

For a put option in the non-trading book, where there is no guaranteed minimum payment and the price will only be determined after the occurrence of specified events i.e. there is no strike price for the put option, how would the notional amount be calculated in accordance with Article 15(f)(1)(b)(ii) of Regulation (EU) No 241/2014?