A bit confusing, those descriptions!
Normal descriptors are 'anti-clock' and 'clock', ' Spring right hand' or 'Spring left hand' for manual camrings - and 'fixed' for mags designed for use with ATDs. Counter-intuitive to see handedness and fixed in the same phrase . . .
Right hand (usually!) means the cable comes into the camring housing from the rh side looking from the cb end (and Left hand the lh side).
The side of entry affects whether a mag is slack or tight advance:
Left hand, anti-clock drive, and right hand, clockwise drive give slack cable advance.
RH AC/W or LH C/W mean tight advance.
Some of the later K2FS had camring housing castings with blank bits, which weren't drilled and tapped for AR cable fitment, although they could have been, still can be. Those blank bits came on either side . . . so I wonder if that's how the words 'fixed' and 'side' can get into the same phrase. Not sure!