Halliday & Matthiessen (2014: 382):
We may also use the term ‘embedded’, taken from formal grammars; but with the proviso that this term is often used to cover both rank shift (where the item is downgraded as a constituent) and hypotaxis (where the item is dependent on another one but is not a constituent of it …). Here we shall use embedded only as an alternative term synonymous with rankshifted.