The Hymn Code ヒュムネコード, hyumune koodo?, lit. "Hymmne Code") is a special identifier owned by each Reyvateil, which serves to register her access permissions and general Cosmosphere settings. Only Origins, Pureblooded β-Types, and γ-Sublimates possess this identifier due to being artificial lifeforms that got their FFT Spectra registered into the Tower's servers during their creation, while on the other hand, Third Generations don't have them due to not getting their spectra registered at the moment of their awakening to their Reyvateil abilities.