You will find this setting at Dashboard -> Support -> Settings ->Open Ticket Widget. Below are settings available:
This setting will allow you to manage ticket widget that are displayed at sidebar of ticket. It will allow you to edit widget title, widget type i.e. if set enable, it will show ticket widget in ticket and selects the role of which users can see this widget. You are not allowed to delete a widget but you can view it in your own order in ticket.
Following are the widgets available by default :-
This widget is displayed in open ticket page along with its current status, priority and category of a particular ticket. Administrator or Agent has authority to change status, priority or category of a ticket.
It displays the name of a Customer or Agent or Administrator in a open ticket page who created this ticket. If current user is Administrator or Agent then it has authority to edit name or email address of a ticket creator.
In open ticket page, Agent or Administrator can have authority to assign agent who can view this ticket, can post reply, edit, etc.
It displays ticket fields or custom fields in ticket.
Agent Only Fields
This field is visible when agent opens a ticket. If he has access he can edit it, change it and then are displayed in ticket.