The shirt worn with a tuxedo should always be plain white with a stiff collar, pleated front and either studs or mother of pearl buttons to close it, according to Black Tie Guide. The shirt should lay flat over the chest and not bunch up. As with most aspects of wearing a tuxedo, these dress code rules are fairly rigid and do not allow for a lot of interpretation.
According to JoS. A. Bank Men's Apparel, tuxedo shirts come with two different types of collars. Point collars fold completely over to cover the neck and have long points that extend down to the collarbone. Wing collars, on the other hand, have shorter folds that do not completely cover the band of the bow tie and subdued points that only extend about an inch down the neck. Either one is acceptable for black tie dress, though point collars tend to look more classic and wing collars more contemporary.
A tuxedo shirt should be worn tucked in to the pants. Some shirts have small loops on the bottom that attach to buttons inside the pants to prevent slipping. The bottom half of the shirt should be covered, either with a waistcoat or a cummerbund.