(20)Data that is used for preparing the information contained in the key information document, such as data on costs, risks and performance scenarios, may change over time. Changing data can lead to changes in the information to be included, such as a change in the risk or costs indicators. For this reason, PRIIP manufacturers should establish periodic processes to review the information contained in the key information document. Those processes should include an assessment of whether changes in the data would necessitate a revision and republication of the document. The approach by PRIIP manufactures should reflect the extent to which the information to be included in the key information document changes, for instance for an exchange-traded derivative, such as a standardised future, call or put, there should be no necessity to continuously update the key information document as the information required for these instruments on their risks, rewards and costs would not fluctuate. Periodic reviews may not be sufficient in cases where the PRIIP manufacturer becomes aware or should have become aware of changes outside the periodic review process that may significantly impact the information contained in the key information document, such as changes to a previously disclosed PRIIP investment policy or strategy that would be significant for retail investors, or significant changes to the cost structure or risk profile. For this reason, PRIIP manufacturers should also be required to establish processes for identifying situations where the information contained in the key information document should be reviewed and revised on an ad hoc basis.