I think that the specific tests may have their own terminology. On an SB-V report, there are Descriptive Classifications next to scores-- 99.9->99.9 interval percentile -Highly Advanced (Profoundly Gifted), 99-99.9 interval percentile - Very Advanced (Exceptionally Gifted), 95-99.7 - Highly Advanced (Highly Gifted). Not sure if that was the tester's terminology or if that comes straight from the test.

Also, I believe age will make a difference in whether a score of 19 is less than or greater than 99th percentile. The older you get, the more likely you are to have company at the top.