Is it possible to completely hide the department field on the pre-chat form?
The department field can be hidden from visitors by calling the $zopim.livechat.departments.filter function with an empty string parameter.
This will prevent visitors from selecting a department. A department can still be set using a trigger or the $zopim.livechat.departments.setVisitorDepartment function. For more information on automatically setting the department via trigger or API, see the following articles: