I am writing a music theory ebook which heavily uses an embedded font called "Opus Text". This font contains characters for music symbols and notation. Some of the characters display correctly in the Readium ebook viewer. For example the lower case b is the musical flat sign. This character displays as a flat sign everywhere it is needed. The same is true of the # sign which is the sharp symbol.
However, the capital X character is the musical symbol for a double sharp. This character, however, never displays correctly according to the embedded font face. It is always shown as a capital X rather than the double sharp sign. This is also true of the § character which should be the musical symbol for a natural note.
A number of characters display correctly and a number of other characters display incorrectly. Is there some reason why certain characters are read in from the font and displayed correctly and others are not?
Is there anything I might try to make the entire character set from the font display in readium?