Often called the Eaton collar mainly because it was designed at Eton University, the club collar is simply an ordinary stage collar with edges that have been rounded off, so they don't have “sharp” edges to them. There's also shirt collars which are pretty compact using a minimal spread, among https://types-of-collars-shirt86162.tribunablog.com/what-does-types-of-collars-shirt-mean-41510139