The ring finger is the only part of the body to be named after the jewellery you place on it. Rings are worn directly on the skin, but they are also visible to everyone. They make it easy to display your affinity with another person or a particular group. Rings are also an acceptable option for people who otherwise wear very little jewellery. Some men limit themselves to a wedding ring, for instance, or bishops to their ring of office. It was long believed that a vein, the vena amoris, ran directly from the fourth finger of the left hand to your heart, making that finger the ideal place to wear a love token. Rings were used to signal betrothal or marriage as early as Roman times. Any ring could actually serve this purpose: iron, bronze or silver ones with two linked hands, known as fede rings, for example, were popular for many years. There is still no specific shape for an engagement or wedding ring, so smooth, gold bands or rings set with precious stones or diamonds are often used today to symbolize a loving relationship. Modern jewellery designers continue to play with the meaning and form of the wedding ring in their work.