Chalk it up as another bug, I'm afraid. It's supposed to render as a treble clef. Very sorry Garry. My recollection is that I tried to get that to render in a font that would have the correct unicode but something appears to have gone sideways.
No problem. After asking this question, I realised that the context implied that the single character was a clef and I noticed that the other unknown characters actually changed each turn, so I assume they are musical notes (crotchets, quavers etc.).
