When you open an item of feedback, you can add notes. This is a helpful place to record phone calls, or to let colleagues know how you’re dealing with the feedback. Everyone at your company can see the notes, but they are never shared with your customers.
An example note…

By default, a note on someone else’s feedback offers to email the owner. If you’re the owner, it offers the person who most recently assigned it to you. On unowned feedback, nobody is selected by default — you can still pick colleagues manually.
Some follow-up actions can include a note as part of the action itself:
Those notes appear in the timeline with the action. The email for that action already includes the note, so it isn’t sent again as a separate note email.