Now, .cutekit/extern/skift-org/karm/src/karm-core/base/base.cpp does contain an export using definition for f16, but it's a) commented out and b) ifdef-gated behind a __FLT16_MANT_DIG__ flag which doesn't appear to be set anywhere and there's no documentation on how to pass defines to cutekit. Not submitting a pull request because simply uncommenting that bit is unlikely to be the desired solution, largely because I don't understand what these what-are-essentially-fancy-typedefs are being used to achieve (in the grand scheme of things, not mechanically), it's either "modern C++ wisdom" that's beyond me or the other way around, but in either case I'm the wrong person to decide what to do with them.