Halliday & Matthiessen (2014: 306):
It may be the content of what is said; e.g. your family in But when people describe your family, they don’t talk about your nephews and nieces; … The Verbiage may construe the topic of what is said, as with describe your family above; as the following clause illustrates, this type of Verbiage is close in meaning to a circumstance of Matter (talk about your nephews and nieces). If the verbal process is one that projects goods-&-services rather than information, like order or promise, the Verbiage refers to these: e.g. a steak in I ordered a steak, those earrings in those earrings were promised to another customer.