U+2111 gets wrong glyph in HTML-CSS and SVG output
The block-letter capital I at U+2111 is appearing as a J rather than an I in HTML-CSS and SVG output with the MathJax font.
It turns out that the font data for the MathJax font is wrong for this (it remaps to the Fraktur font, but has the position wrong).
0x2111: [0x004A,MML.VARIANT.FRAKTUR],
should be
0x2111: [0x0049,MML.VARIANT.FRAKTUR],
in fontdata.js
for both HTML-CSS and SVG versions of the TeX fonts.