It's not a "bug" of this font. PUA can be used in any way by any fonts. This problem is because Un-fonts precedes Font Awesome in your fontconfig configs.
** Changed in: fonts-unfonts-core (Ubuntu) Status: New => Opinion -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1531126 Title: Usage of Private Use zone(0xE000 - 0xF8FF) in "UnDotum" font causes Font Awesome icons rendered wrongly in Mozilla Firefox To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fonts-unfonts-core/+bug/1531126/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs