"The freedmen of Roman Citizens normally entered into the Roman citizen body, but they were ineligible for Equestrian or Senatorial rank, for the highest Roman and municipal magistracies, and for the military echelons reserved for freeborn citizens; and in Rome they were the subjects of severe social discrimination, being treated as upstarts. [. . .] Freedmen staffed many of the innumerable menial and clerical posts in the municipal and imperial administrations, and the priesthood of the cult of Augustus (seviri, "board of six") was practically reserved for them. This office of Augustalis, the discharge of which involved considerable expense for its incumbents, was the pinnacle of a freedman's career, except for those of their own freedmen whom the emperors appointed to the important administrative procuratorships and the imperial secretaryships."

Lewis, Naphtali and Reinhold, Meyer, Roman Civilization: Selected Readings, Volume II: The Empire, New York: Columbia University Press, 1990, p. 167-8.

The following is from an inscription containing Tiberius' reply to a c. A.D. 14 decree of the Greek city of Gythium:

"Tiberius Caesar Augustus, son of Augustus, pontifex maximus, holding the tribucian power for the . . . year . . . to the superintendents and city of Gythium, greetings. Decimus Turranius Nicanor, the envoy sent by you to me and my mother, transmitted to me your letter to which were appended the measures passed by you in reverence to my father and in my honor. I commend you for this, and consider it fitting that all men in general and your city in particular should reserve special honors befitting the gods in keeping with the greatness of my father's services to the whole world; but I myself am content with the more modest honors appropriate to men. My mother, however, will answer you herself when she learns from you your decision about honors to her."

"About the same time [A.D. 25] Farther Spain through envoys sent to the senate requested permission to erect a shrine to Tiberius and his mother, following the example of Asia. On this occasion the emperor, vigorously scornful of honors in any case, and considering that an answer was due to those who in their gossip charged him with having descended to vainglory, began a speech of the following tenor:
'I know, Senators, that in the eyes of a good many of you I was lacking in consistency inasmuch as recently when the cities of Asia made this same request, I offered no opposition. I shall therefore disclose both a defense for my previous silence and what I have determined for the future. Since the deified Augustus had not forbidden the erection of a temple at Pergamum to himself and the city of Rome, observing as I do his every action and word as law, I followed the precedent already approved by him all the more readily as reverence for the senate was associated with worship for myself. To have accepted once is pardonable; but to be consecrated in the image of deity through all the provinces would be pretentious and arrogant, and the honor paid to Augustus will become empty if it is vulgarized by indiscriminate acts of flattery.
As for myself, Conscript Fathers, that I am mortal, that my functions are those of human beings, and that I hold it enough if I occupy the foremost place--this I call upon you to witness, and I desire posterity to remember. For they will do justice, and more, to my memory if they believe me worthy of my ancestors, solicitous of your interests, firm in danger, not fearful of offense for the sake of the public welfare. These are my temples in your heart, these are my fairest and abiding statues. For those that are erected of stone, if the judgment of posterity should turn to hatred, are scorned as sepulchers. Accordingly, my prayers to allies, citizens, and the gods themselves are these: that to the end of my life they may endow me with an unperturbed mind, gifted with understanding of human and divine law; and to the others that, whenever I depart, they may escort my deeds and fair name to the tomb with praise and kindly remembrances.'
And henceforth, even in private conversations he persisted in spurning this worship of himself."

Tacitus, Annals IV. xxxvii-xxxviii

"He forbade the decreeing of temples, flamens, and priests in his honor, and even the setting up of statues and busts without his permission; and these latter he permitted only on the following condition, that they were not to be placed among the statues of the gods but among the adornments of temples. He was opposed to an oath being taken in support of his acts, and to changing the name of the month of September to Tiberius and of October to Livius [in honor of his mother Livia]."

Suetonius, Life of Tiberius xxvi