You may have noticed that we have begun numbering our refreshes. The April 15, 2017 refresh is number 66 in a long line of tools refreshes.
We abbreviate the April 15, 2017 refresh as *R66*.
Why do we call this a "refresh"?
We do a simultaneous refresh of the tools across all of the underlying supported releases of the IBM i Operating System. To call this a release or version would confuse it with the VRM numbering of the underlying OS, since we refresh the tools far more often. You could consider this our parallel to IBM's Technical Refreshes for IBM i, but our refreshes apply to multiple VRMs of the IBM i OS.