In Persius' 5th satire, in the framework of an argument about true freedom, a slave mentions a case taken from everyday life, that of manunissio vindicta. After the praetor's court the emancipated slave is free to do anything except what is prohibited by rubrica Masuri. The author puts forward a hypothesis explaining this essential but not directly named restriction of an emancipated slave's capacity. Modern scholars tend to interpret the mention of rubrica Masuri as a definite reference to Masurius Sabinus, rubrica thus being taken metonymically for «law» in general. But in singular this term always bears a specific meaning and implies particular prescriptions (cf. Fr. Vat. 227; Paul. 63 ad ed. = D. 43. 1. 2. 3), in which rubrica corresponds to titulus, a section of the praetor's edict. Therefore, a translator and commentator of Persius' satire cannot content himself with interpreting Masuri rubrica as general reference. The author of the paper maintains that the poet uses the expression to hint at a commonly known (?) legal restriction resulting from manumission, a restriction which was introduced after Sabinus' intervention. To ascertain legal implications of Masuri rubrica, she compares it to a passage in Aulus Gellius (NA. 5. 19. 11-12) citing a text written (scripsit) by Masurius. This text acknowledged adoption of an emancipated slave by a free-born person, but did not allow the former slave to receive rights of the free-born (neque... per adoptiones in iura ingenuorum invadant). This means that the slaves emancipated in this way did not become free from, e.g., their duties to their patron and his family or from prescriptions of public law, such as lex Visellia of 24 AD. In the authors opinion, these two texts could be connected in the sense that Persius' rubrica Masuri referred to Sabinus' clearly formulated attitude towards adoption of freedmen, the attitude which consisted in the prohibition (cf. Persius' vetare and Gellius' nonpermittere) to «assume» iura ingenuorum.