In reply to Ronald J. Fehd.

Hi Ron,
Thanks for bringing light to this important concept. Both Chris and I picked up on your work. See 'props' (page 6) :-)
http://minnsug.org/wrp/wp-content/uploads/2013/10/Beyond_NLEVELS_MinnSUG_20131017_CAJ_final.pdf
Great work Ron.
Carole