Halliday & Matthiessen (2014: 270):
Attribution of the ‘entity’ kind approaches qualitative attribution when the Thing in the nominal group is a very general one such as thing, person or fellow. Thus in I started it in Paris in late ‘51 with a guy called Harold Humes, who was an absolutely brilliant fellow but rather erratic, the attributive nominal groups an absolutely brilliant fellow (Thing/Head) and rather erratic (Epithet/Head) are both qualitative characterisations;