Taekwondo is spelled as one word, which to me is easier to type.
It's correct either way. I simply choose to spell it in the same way my Tae Kwon Do teacher spelled it. If someone chooses to spell Karate as Kara-Te or Kara Te, it's fine either way, as long as they stay consistent (especially for business purposes...).
It's no different than Korean folks living in English-speaking areas (or German, French, Spanish, etc) spelling their names as they want to spell it. For example, Kim Dae Jung could be spelled as Kim Daejung, Dae Jung Kim, or Daejung Kim, and any of those would be correct.
But in any event, what part of the back is a scoring area under the USA-NKF rules? The back is also a legal scoring area under both the USAT and WTF sparring competition rules.
Anywhere except the spine or kidneys.
I don't know if George Kotaka and Elisa Au compete with the USA-NKF.
These days, they're more ambassadors and coaches, but they did, indeed, compete a lot with the USA-NKF, and both represented the USA at the WKF tournaments (pretty much the same rules).
They might be more AAU competitors, although I have to say I don't really follow closely enough to know the difference. But both trained under a taekwondo student of mine, working on their footwork and primarily back leg roundhouse kick. It was slow going in the beginning, but then they understood and caught on real fast after that. Soon thereafter, I saw George competing at the Titan Games, and was surprised to see him moving like a taekwondo competitor, using steps and scoring with his back leg off the line roundhouse kick.
George Kotaka was always hungry for knowledge, adding anything that he could to improve his game. He regularly trained with other dojos in the area as well, even ones that were seen as his father's competitors. He's a great guy to have around, and is a inspiration to everyone with whom he trains. Best of all, he's a class act. I hope that he continues to inspire the US Karate team competitors, since everyone can learn from him.
Replacing him on the US team isn't going to be easy at all, but thankfully, the US has a deep talent pool, and an excellent array of coaches.