When you're in a Ticket, you can turn earlier answers, that you or your colleague(s) have sent, from Public to Private. You do this by clicking the three dots in the upper right corner of the specific message that you want to make private, and then clicking Make message private.

The answer is then marked with a light yellow color, that indicates that the answer has been made private.

The Make message private feature is good if you've happened to send an answer to the wrong e-mail address and are going to resend the answer to the right e-mail address. Then you can make the message, that you'd sent wrong, private before you resend the answer to the right e-mail address. Private messages won't be visible to the receiver, you see.

Another example of how you can use the Make message private feature, is if you've received a Ticket that you don't know the answer to. Then you can forward the question to a colleague who's got the right answer. When the colleague has answered again, you want to answer the requester without having the history between you and your colleague visible to the requester. Then you can make the messages between you and your colleague private before answering the requester.

If you want to make the message public again, simply click Make message public.