The polo coat. There's a continuum on which all overcoats, indeed perhaps all garments, sit, which at one end is labelled formal and at the other is flamboyant. It's not a theory much honed, and on reflection might have multiple axes, since probably a coat can be both, but in any case, the polo coat here is quite flamboyant.
It has a semi-raglan sleeve, which nods to the peculiar split set-in sleeves of very old polo coats — the distinctive seam running down the flank of the arm — but brings also breezy comfort and ease.
It has especially large patch pockets, too, which when rendered in cloth of the chunkiness on display here seem to have as much heft as some other garments do in entirety.
And it has only two buttons, an optional extra really, in salute to the traditions of polo coats of more than a century ago, when the standard use-case was being slinked on and off in and around actual games of polo, and thus such coats were treated more as outdoor dressing gowns — has laissez ever been more faire — rather than regular everyday outerwear.
The polo coat is lined halfway down the back with a smooth and slinky satin, cut as a single panel. It helps with sliding the coat on and off, being as the outer cloth has the potential for friction. The sleeves, too, are lined with the same cloth.