G71 in LinuxCNC 2.9

MRx wrote:

>> When in absolute mode the U (for X) and W (for Z) can be used as
>> incremental displacements.

this I don't really understand, because there's no U/W in the command interface?

I am not sure that I understand what it is that you don't understand, but the parsing of the G71 block is done by a different "interpreter' to normal, and a few command letters have very different meanings (specifically A, C, U W, do not refer to axis movement inside a G71 block, or at least not _those_ axes)