Tools - Audit Trail - Settings

Ribbon bar. Select the Tools tab. Click Audit Trail and from the menu, select Settings...

Classic menus. From the Tools - Audit Trail submenu, select Settings...

...to display the Spreadsheet Audit Log Settings dialog box, which is used to specify the settings for the spreadsheet audit log. You can enable audit trail logging and require users to give an explanation for each change made to the spreadsheet. An option for truncating (or clearing) the log is also available.