Yes, this is another problematic webfont -- specifically
"adobe-clean-han-japanese". However, Adobe is loading it by
embedding it as data, not by referencing it as a URL. This is not
merely an issue of loading it into the blacklist; I need to block
these also and I don't have a mechanism yet. I won't be able to
address this for 38.4, which is already being built.
Blacklisting a font is what we do when the font cannot be
displayed by the operating system (10.4) and/or will make it crash
(10.5). If we didn't blacklist it, it still wouldn't show, so yes,
they're uniformly considered incompatible. Even Safari can't
display them, but it uses a method of detecting them that is not
compatible with 10.4, so we can't use it.