This is an interesting question, and everywhere I turn different definitions are used. Hogies doesn't list any of the tests my kids were given. The older two I don't even have FSIQs for because of their 2e-ness, only GAIs were computed for us.
DS#1 and DS#2 I consider MG or just plain ol' G. They match the descriptions for levels 3 and 4 and have scores in level 3 on the page in Crimson Wife's link, don't qualify for DYS, and seem average in some areas and ahead in other areas compared to the kids of my old college friends (who all test G by the PS). However, on DS#2's private psych report he is described as "highly gifted," and OTOH our PS's psych scoffed at DS#2's scores and basically told me that he wasn't "really" gifted at all (and then he got into the public GT magnet... so mixed messages there too).
DS#3 I'm calling HG. He very easily qualifies for DYS, but his scores are also very "pointy" (I guess?), because verbal was 45 points lower than non-verbal, and he hit half the subtest ceilings for everything excluding verbal. Admittedly he has had 3 recent surgeries that affect hearing and speech, so I don't know if verbal ability can or should be gauged atm. On the page Crimson Wife linked to, his scores are well above level 5, but he doesn't match any of the descriptions at all. If I only had that list to look at, I'd guess he was just weird, lol.
I feel a little untrusting of IQ scores in general now. I think there's a lot they simply don't measure, like DS#2's crazy non-linear thinking and incredible creativity. I would guess that all three of my older kids are similarly gifted, just with different strengths and areas of relative weakness, but that's not what the tests show. DS#3 has scores way, way above his older brothers. But you know, he walked, talked, and began reading at the same ages as DS#2, who scores lowest among my older boys. Academically, he's about a year ahead of where DS#1 and DS#2 were at 5yo, but he's also been exposed to much more academics than the other two were by this age.
I think a person can be HG+ in nonacademic areas and score well below that on tests, and high scores do not guarantee success or a particularly exceptional list of accomplishments. My paternal family and paternal half-sibs all score in the +4 to +5 SDS range, but all have normal lives, normal jobs, and seem like regular smart people. A few could even qualify as "failures" or did poorly in or dropped out of school. Ultimately, IQ is just a number, just one dimension of giftedness.