Comments can be added to a case when it is created, when reviewing a case and even after it has been archived. Open cases can only be commented on when a case is owned; if it was sent to a group, the user must take the case before being able to add a comment. Comments cannot be added to a case that is owned by someone else.
To add a comment to a case:
Step 1: From the Case screen, click on the Add Comment button. A comment field opens at the bottom of the screen.
If the Add Comment button is not visible, make sure that the case is owned.
Step 2: Enter text in the Comment field and click on the Save button. The comment is added to the case and will be seen by those reviewing it.