Prom garters were common in the 1960s & 70s, and often conferred on the date as a souvenir. If the date received the garter, it was typically hung from his rear-view mirror.
Beginning in the mid-2000s, it has become common in the United States for young women attending a high school prom to wear a garter, usually designed to match the style and color of the young woman's dress.
The prom garter may be worn throughout the evening and is sometimes given to the young woman's date as a souvenir. A young woman may also choose to keep the garter rather than give it away, as a token of her prom night.
In some cases, young people may participate in a "garter and tie" dance (often hosted by the high school as part of the prom), during or after which either the young woman herself or the young woman's date removes the garter and exchanges it for the date's tie. In cases like this where the garter is given early in the evening, the young woman's date may wear it on his arm for the remainder of the evening.
In areas where prom garters are common, it has become a tradition for young women to pose for a picture with other female friends before the prom, in which they pull up the skirts of their dresses to display their prom garters, which are generally worn a few inches above the right knee.
The giving or taking of the prom garter may or may not have the same sexual implications that are associated with wedding garters; however, the giving of the prom garter is often interpreted as publicly designating the pair as a romantic couple.