(18)Taken together, the proposed temporary measures should address many – but not all – of the differences in the level-playing field between major jurisdictions. To preserve, during the transition period, a level playing field until major jurisdictions finalise and implement the FRTB standards, credit institutions that are adversely impacted by the FRTB rules should be allowed to limit the impact of those rules on their capital requirements by applying a multiplier lower than or equal to 1 to those capital requirements for the three-year period of this delegated regulation. Given that those credit institutions are affected by the new framework to a different extent, the calibration of the multiplier should be bank specific. Furthermore, as credit institutions would apply the multiplier until 31 December 2029, they should be able to recalibrate the multiplier periodically to a reliable benchmark to account for changes in their portfolios and in market conditions. It is therefore necessary to introduce a multiplier that scales down the impact of the new rules to the level of the previous Basel 2.5 implementation. To enable that precise calibration of the multiplier and avoid excessive operational complexity, including the application of multiple boundary concepts within the same institution and changes to the models used under the Basel 2.5 framework, it is necessary that the multiplier is calculated using the trading/non-trading book boundary under the Basel 2.5 implementation. Credit institutions that are eligible for and are choosing to apply the multiplier from 1 January 2027 should also have the choice to stop using it before the three-year period lapses, but they should not be allowed to resume the use of the multiplier later on. Reporting and disclosure requirements are essential tools to enable supervisory oversight and market discipline. Hence, credit institutions that choose to apply the multiplier should also continue to report and disclose information on their binding own funds requirements in accordance with the Basel 2.5 implementation, using the relevant provisions laid down in the version of the CRR in force on 8 July 2024.