@punktphil looks like that's being introduced in 3.5. You'll find that as features get added to the firmware (at pre beta and beta stages), they'll get documented as it's easier to create the docs when you add features rather than remember to go back and do it.
So for the time being, you can't use K

@rzi said in Any progress with variables / parameters?:

Sounds super! Not that far away then. Are you planning to do a similar implementation as in: http://linuxcnc.org/docs/html/gcode/overview.html#_parameters

Or are you heading in some other direction?

Best regards
Rickard

I looked at the linuxcnc implementation, and it's horrible. There is another thread on this topic in which I linked to the draft specification of what I am implementing.