I've seen on Pixiv that パーカー seems to be used as kind of a general term for hoodie, but searching "parka" in English tends to get me something more specific (heavier-looking, sometimes with fur). Maybe this is a similar case to jersey, where the Japanese use causes some confusion and cleanup is needed? I noticed it was discussed briefly in forum #34893 though the other issues in that thread seem somewhat unresolved too.
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