Heraldry is the science of devising appropriate "bearings" (emblems) for military armor and determining the right of persons to certain arms or bearings through genealogical study. Heraldry has also been applied to the seals and coats-of-arms of religious organizations. In 1307 religious houses in England were ordered to have a common seal. The miter, the crozier, and the ecclesiastical hat appeared as emblems in the fourteenth century.
Ecclesiastical heraldry is visible today in the seals of many dioceses. It is interesting to note that the seal of some dioceses has a cartouche or oval design, while other dioceses employ a shield design for the seal. The shield is a military symbol, and its appropriateness for use as a diocesan symbol may be questioned. Many diocesan seals include a cross, or other religious symbols. Some diocesan seals incorporate one or more symbols that are associated with the location of the diocese. For example, the seal of the Diocese of Milwaukee displays a badger, which is associated with Wisconsin, "the badger state." Some parishes and other church organizations also have seals.