Oddly in Firefox the tab name showing the title only gets as far as πΌππππ before giving up with what looks like a box with D835 in it.
I still don't know what the sequence is though, any Unicode expert to explain? Apparently is d835 "invalid"?
http://www.charbase.com/d835-unicode-invalid-character
Edit: I see now emillon explains:
"U+1D48F whose UTF-16 BE encoding is d8 35 dc 8f."
That's:
"MATHEMATICAL BOLD ITALIC SMALL N"