Altar servers assist the celebrating priest. The servers duties are to bring/or oversee the bringing forward of the Sacraments. They are also assigned the duties of ringing the Acolytes' bell at specified times during the Mass. They may also be required to assist with the lighting of the incense burner, and, at times, the distribution of incense.The servers wear special vestments,and need to be ready in advance of the start of Mass.