Keyboard actions fkeyN starting from fkey13 (Shift F1-F12, Ctrl F1-F12, etc) don't generate any code. It affects vt(4) console under 11.0-RELEASE with kbdmux or atkbd driver. It doesn't affect sc(4). Also it doesn't affect vt(4)/10.3-RELEASE and older.
How to reproduce:
1. Set system console to vt(4) mode if it's in sc(4) mode.
2. Execute 'cat' command.
3. Press F1-F12 - works as expected.
4. Press Shift F1-F12 - doesn't work.
It's reproducible in virtual environment too (at least with qemu).
Is there any update?
(In reply to vvv from comment #1)
Looks like vt emulation is limited to F1..F12 by design:
the key is then passed to teken/teken.c code that also handles only up to F12:
Extending that list to more F keys shouldn't be a problem from implementation point of view but i am not sure whether it's going to violate any standards. Adding Ed to Cc so may be he can provide some input.