Traditional Kilt Jacket Backs?

[Bugbear]

I have a kilt jacket and it has two side vents instead of the single middle vent of the suit jacket type. Other than that, it looks the same but is tighter on the body, more fitted.

I think some of the daywear jackets have folds or darts up around the shoulderblade area, and other places that help make them fit while still being flexable. The side vents are on most of them, but I'm not sure all side vents are made in the same way. For all I know, though, there might be styles of kilt jackets without any vents.