Most Eastern Catholic Churches still resist using female altar servers. One of the reasons is a long-standing tradition that only males are allowed behind the iconostasis, and then only for a valid reason. Also, there is sometimes an understanding in the Eastern Churches that serving at the altar is meant to aid in the discernment of a vocation to the diaconate or priesthood. However, some Eastern Catholic parishes do have altar girls today. This is increasingly common among Ukrainian Catholics, for example.