I can't remember where I've seen jackets in this style (I thought it was David Tennant's Doctor Who), but I found it quite cool-looking and wanted to learn more.
I don't know what this style is called, and I can't find any pictures. I've mocked it up here.
It's essentially extra fabric in the upper back, such that if you extend your arms out it won't bunch up. But if you stood normally the fabric folds in.
I've tried to show where this vent would be. Does any of this make sense to anyone? Can anyone point me in the right direction?







