Halliday & Matthiessen (2014: 652):
The systems of THEME, INFORMATION, REFERENCE and ELLIPSIS are all concerned with textual statuses. Speakers assign these statuses to components of messages to help themselves produce texts and to help their listeners interpret them. These textual statuses are independently variable. For example, thematic status may be combined with either given or new, and the same is true of rhematic status. However, there are certain unmarked combinations: in the unmarked case, Theme is Given and New falls within Rheme. The thematic statuses and the favoured combinations are shown in Figure 9-5.
