Contact the admissions office for the university to confirm what they do an don't want.
I have found that they are truly eager to help and answer any questions you might have, so rather than sit confused with the application in front of you or go off our best guesses, better to get it straight from the horse's mouth, no?
One of the schools I was considering applying to for transfer requires a HS transcript with the application, regardless of how long it has been since I graduated, while the other only requires it once you are accepted as means of class placement/prerequisite check (which seems pointless since I have 60+ hours off CC credit to attest to/qualify for that, but whatever). I also had to submit an extended resume and my admissions advisor indicated that was where I could go into detail about both my HS and CC ECs, because the application was designed to cater to freshman applicants and didn't really work for transfers. The more time that passes since you left HS, the less important all of those scores and activities matter, but for some reason some schools want to have it, and as Laurenney said, if there was something interesting or remarkable that happened back then, it probably won't hurt you to bring it up, it's just not usually necesssary.