hyco

Hyco is just a shorter version of the Term Hypercommunity, which makes them a whole more easier to express and understand.

Essentially saying, when Hyco is said, they meant to mention for a community that has an elevated amount of advancements, words, cultures or/and details that make it unique... Or closed, because it's likely to target those who have a closed/negative opinion on it.

For an easier example, these communities are classified as a Hyco:

The Government (not kidding), Chess Community, Splatoon Community/Fandom, Sonic the Hedgehog Fandom (a.k.a. mobian), Furry Community/Fandom, BFDI Community, My Little Pony Fandom (a.k.a. Brony) and etc etc etc....