In the input fields of Local Chat, Group Chat and Private IM Chat users can press CTRL + Up/Down arrow to scroll back the history of the chat messages they previously sent.
Currently, this feature isn't adverted to the user. Viewer doesn't show in any way that this feature exists and how to use it.
A new UI Hint should be created to give users information about this.
If UI Hints are not appropriate, a different way to convey this information to the user should be used.