The overdues alert on patron accounts contains a "See highlighted items below" link that jumps to the Checkouts table and shows checkouts if they are hidden. Currently, the link uses an "onclick" attribute to show hidden checkouts, which is against coding guideline JS9 (https://wiki.koha-community.org/wiki/Coding_Guidelines#JS9:_Avoid_the_use_of_event_attributes_like_.22onclick.22_to_attach_events). This should be revised.