How are note names rendered into the note heads?

Musescore can render note names into note heads, like C, C# ... or even solfege like Do, Re, Mi.

Are these rendered as seperate characters? i.e. for Do, is the D and the o rendered seperately? i see that in the final render output the "o" is raised slightly while the D is at the baseline, giving an impression of "o" is used as a superscript to "Do".

I looked into the internal glyphs of the mscore font, but didn't find the required glyphs for "Do"