The Hoagie's Gifted page that attempts to quantify levels of giftedness defines "highly gifted" as 145+, and "profoundly gifted" as 152+, 175+, or 180+ depending on the instrument used to test. (It does not include the WISC-V, the most recent test edition, in its definitions.) Davidson, on the other hand, defines "profoundly gifted" as starting at 145. I think that George is correct in stating that Hoagie's and Davidson are using these words differently, and that "Davidson PG" is roughly the same as "Hoagie's HG".