Originally Posted by yogawordmom
... I'm not sure of the exact meaning/scores of G/HG/PG...
Welcome! Hoagies' Gifted Education Page may be of interest, especially Highly, Exceptionally, and Profoundly and What is Highly Gifted? Exceptionally Gifted? Profoundly Gifted? And What Does It Mean?

While the cut scores vary by test instrument,
Profoundly > Exceptionally > Highly > Moderately gifted.

HG+ is an informal, unofficial umbrella term for Highly gifted and above. It would include Highly, Exceptionally, Profoundly gifted.