Overlays are one way of informing the engineer that some event has occurred concerning a ticket. As described in section The Properties Editor (Example: Activity), subsection overlay, an overlay can be set using the Process Designer GUI, namely the properties editor of an activity. In numerous cases, it is sufficient to configure the removal of the overlay by using the overlay range. However, in some cases it might be required to set or remove an overlay using a workflow script. The most common example of this is the removal of the mail overlay when an email has been read. A detailed example of working with overlays for this use case is provided in section Use Case 2: Overlay for Ticket Icon and Email Confirmation by Engineer.