The term "Codex Vaticanus" refers to a historic manuscript that is over 1600 years old. It is considered to be one of the most important sources for the original text of the Bible. The term can also be referred to as the "Vaticanus Codex" or simply as the "Vatican manuscript." Other synonyms or related terms include "B," "03," and "Vatoyannis Codex." This ancient manuscript is written in Greek on vellum and contains the Old and New Testaments as well as some additional books. It can be found at the Vatican Library in Rome and remains one of the most significant documents in the history of Christianity.