If an XML document is transformed to PDF using the built-in Apache FOP processor but it
contains some Unicode characters that cannot be rendered by the default PDF fonts, then a
special font that is capable to render these characters must be configured and embedded in
the PDF result.
Important: On Windows, fonts are located into the
C:\Windows\Fonts directory. On macOS, they are placed in
/Library/Fonts. To install a new font on your system, it is enough to
copy it in the
Fonts directory. If a special font is installed in the
operating system, there is a simple way of telling FOP to look for it. See
the simplified procedure for
adding a font to FOP.