The rota is one of the symbols used by the Pope to authenticate documents, e. g., Papal bulls. It is a cross inscribed in two concentric circles. Pope Leo IX was the first pope to use it.
The four inner quadrants contain: "Petrus", "Paulus", the Pope's name, and the Pope's ordinal number. The Pope's autograph or motto is sometimes inscribed between the concentric circles.
A rota was also used by monarchs for the authentication of documents and diplomas.