Which part of the garment does 'danjak' mentioned in the description refer to?

Danjak is a term that refers to the vertical band where buttons and buttonholes are positioned to fasten the front of a garment. It corresponds to the part commonly called a placket on a shirt, and because hands touch it and force is applied each time it is opened and closed, it is usually finished more sturdily than the outer fabric.

Chunky Rib Cardigan is made with a button closure where that area is finished with rib knitting^[1]. A rib structure is a knit fabric woven with vertical ridges, giving it the property of stretching and bouncing back into place, and in knitwear, it is frequently used in areas prone to losing their shape, such as sleeve ends or hemlines. Using this structure on the front closure helps prevent gaps from opening between buttons or the band from sagging.

There are also garments that utilize the same area differently. Peached Slim Fit Shirt features a developed label from LOW CLASSIC as an accent at the lower end of the placket^[2]. hmmm, the fact that the label is placed not behind the neck or on the inside, but at the very bottom of the front closure, suggests that this band was finished not simply as a functional fastening part, but as a place on the front of the garment where the eye rests.