(13)With particular regard to the internal data, consideration should be given to the fact that even though an operational risk loss can arise only from an operational risk event, its occurrence may be revealed by different items, including direct charges, expenses, provisions, uncollected revenues. Whilst some operational risk events have a quantifiable impact and are reflected in the institution's financial statements, others are not quantifiable and do not affect the institution's financial statements and are therefore detectable from other sources including managerial archives and incidents dataset. Therefore, rules specifying the assessment methodology for competent authorities in order to permit institutions to use the AMA should specify what constitutes an operational risk loss and the amount to be recorded for AMA purposes and, more generally, all the potential items that could reveal the occurrence of operational risk events.