That is correct, but software seems to use left hand rule, axis your thumb is pointing to (direction) is > than origin. Normally it also should be enough to specify any set of points in a space along rotation axis.
If you rotates along Z axis (X,Y being 0), 0, 1 points toward Z POZ. 100, 101 or -101, -100 on the Z axis does the same.
However I was completely misled by my cylinders rotating in both directions in any case they were shifted in X and / or Y axes. As Ruben said that ‘they are working on it’ I stopped to experiment with that setting awaiting the fix. As precaution I decided to define a rotating axis of MRF zone as ‘piercing’ that zone, even if it was centered on 0 of an axis. Sounds like superstition I dislike, but I need this fix first.
In meantime I possibly discovered another problem in CFD, but will tell you in a different thread.