Thanks very much, TOD
Boroda
But, WGS-84 is not a monopoly, it is not even a tradable good, it just IS. ICAO cannot dictate anything, but as a Standard and Recommended Practice, the ICAO said aviation will use WGS-84. Hell, we could use Argentine 1925, just as long as everyone's equipment is compatible and we are all using the same thing.
Considering PZ-90 has been modified to nearly conform with WGS-84, the only alternative we are talking about here is a name. Let's just call it "Fred's Lat/Long System".
GF