Collar tab
Appearance
Collar Tab is that small piece of plastic that is removable and goes insertion into the collar of a male shirt. It keeps the collar errect. On more high priced shirts collar tabs are removable and made of high quality prefabricated materials such as plastic. In lower quality shirts they are not removable and inside the collars at all times.
One can buy a jar of collar tabs in all sizes from a haberdasher. Some boutiques sell collar tabs in exotic luxury materials such as ivory, silver, and amber.