I think DCNH is a little bit more flexible than that though. For example I was typed as a complex subtype "DC" - which the way DarkAngelFireWolf69 explains combined subtypes, this means I operate more as a D when dealing with people with a large communicative distance, and more C when there's a closer distance. My best friend was typed as EIE CH, so he's C at a far distance, and H at a closer distance. And @
SGF is between subtypes, where he could transition to C if he's able to become more contact (less cautious, more stepping in to things, quicker reactions rather than reserved or holding back etc.) In other words, these aren't completely set in stone, there's some give in them.