Activity formatters give you a way to present the audit history of a particular record. Out-of-box, there is an activity formatter set up for the ‘Task’ table (which is available to any of its extended tables). As long as the table is audited, you can use an activity formatter to show a personalized view of the history (and associated sent and received emails) for each record directly on the form.
In most cases, it’s enough just to have an activity formatter on the task tables. You may find it necessary to add an activity formatter to a different table in your implementation. Recently I had a client who wanted to see all of the sent and received emails for approvals associated with a change request. Normally, sent and received emails are displayed as part of an activity formatter but since the Approval (sysapproval_approver) table isn’t a task table it doesn’t have an activity formatter. Since the approval table is audited you can view the history of each record, but you can’t see sent and received emails from that view. After just a few clicks, the client was able to add the formatter to the approval table and see the information they needed. Click here to see the wiki documentation explaining how to add an activity formatter to any table.