A notch collar is a type of jacket or shirt front that typically tops a row of buttons in the garment's center. The notch detail is actually in the lapels that attach to each side of the collar portion that fits around the neck. Rather than a plain straight or curved lapel section added to the neck portion of a collar, a notch, or cut out section, accents each of the lapels. The V-shaped notch tends to give clothing a formal look that has become popular for suits and office wear.