When a mujo daimyo was promoted to joshu daimyo (governor of a castle) or joshukaku daimyo (daimyo without castle, but treated in a similar way to joshu daimyo), he was not allowed to convert his local jinya to a castle but actually was allowed to construct a gate only.
無城大名が城主大名城主格大名へ昇格した場合、国許の陣屋を城に転換することは許されず、実際には城門の構築を許されるのみであった。