The mechanism can be configured in:
Software configuration → Permissions → Admin access → Visits purpose tab
Enabling the mechanism will cause the system to display a popup window each time a user with admin permissions logs in:
All currently available options are available in the Visits purpose tab (Software configuration → Permissions → Admin access)
Here you can also find the login history together with the information about the visits purpose, and filter the results by user, date, purpose, and base user (in case of switching users).