Halliday & Matthiessen (2014: 626-7, 628):
In personal reference, the category of person is used to refer: we described the basic principle in the previous subsection, suggesting that non-interactant personal pronouns and possessive determiners have come to be used primarily in anaphoric reference. The personal reference items of English are set out in Table 9-10. They are either ‘determinative’ or ‘possessive’. If ‘determinative’, they are personal pronouns serving as Thing/Head in the nominal group (as in a velveteen rabbit ... he). If ‘possessive’, they are determiners serving as Deictic in the nominal group and are conflated with either Head or Premodifier (as in a velveteen rabbit ... his coat).
