Halliday And Matthiessen (2014: 678):
… projection includes both hypotactic projection of ideas/reports and pre-projected facts serving in a ‘mental’ or ‘relational’ clause. A hypotactic projection is always ‘subjective’; the speaker is represented explicitly as the Senser (e.g. I presume) or Sayer (e.g. I admit). A pre-projected fact in a ‘mental’ clause is like hypotactic projection in representing the assessment as ‘subjective’ – the speaker is explicitly represented as the Senser (e.g. I regret). In contrast, a pre-projected fact in a ‘relational’ clause represents the assessment as ‘objective’ (e.g. it is regrettable); but it may be ‘prefaced’ by a ‘mental’ clause with a ‘subjective’ orientation [e.g. I think it is regrettable].