Hmm, interesting. Thank you. Is that true that "system Baskerville fonts" don't have them? I never encountered this in my LaTeX documents, but I suppose it's possible my LaTeX distribution is shipping its own Baskerville-like font. I'd need to look into that. I am trying to come up to speed about font sourcing (right word?) on the web. It's also somewhat unfortunate, because as far as my research can tell, I am unable to configure MathJax to use a custom math font.