Dates match: Pope Cletus/Anacletus 76/77/79/80-88/91/92 or 76-79-88-91 (compiled from six different official popes lists). Emperor Titus reigned 79-81. (Proclaimed imperator 70. Titus received title of Caesar in 69 or 71. "Because Titus effectively acted as co-emperor with his father...." Titus on a denarius of c 79. Temple of Vespasian & Titus finished by Domitian. "the Arch of Titus... was not completed until the reign of Domitian." Colosseum building took 10 yrs, begun by Vespasian and finished by Titus.) Both the pope's and the emperor's dates coincide 79-81 (the whole of Titus' reign) (+ 10 yrs). Start dates 79 both the same. End dates 81/91 similar.
Meaning of name Cletus match: The name Cletus/Anacletus/Anencletus may mean "unimpeachable" or else "one who has been called (back)". Of emperor Titus it is said "It is impossible for me to be insulted or abused in any way. For I do naught that deserves censure...." "... keeping his hands unstained". "I have made but one mistake". "Titus proved to be an effective Emperor and was well loved by the population, who praised him highly when they found that he possessed the greatest virtues instead of vices." "Titus's record among ancient historians stands as one of the most exemplary of any emperor. All the surviving accounts from this period, many of them written by his own contemporaries, present a highly favorable view towards Titus."
(Name match? The names "la Clemenza di Tito"/Titus & Cletus look/sound similar.)
Number match: Cletus/Anacletus 3rd pope from Peter (who matches Nero). Titus 3rd emperor from Nero (who matches pope Peter) excluding the 3 "usurpers".
Both are pontiffex maximus. Cletus/Anacletus is bishop / "pope" / "pontiffex maximus" / "supreme pontiff" (Annuario Pontificio, Liber Pontificalis). Titus was pontiffex maximus (the emperors from Augustus to Gratian were pontiffex maximus). "he [Titus] thus kept to his promise that he would assume the office of Pontifex Maximus". "...Titus, (also) dressed in religious regalia." [The argument that the titles pontiffex maximus and pope were not used by/for bishops of Rome until later (mid-5th & mid-6th centuries) and so is an anachronism is not necessarily valid because bishop/pope/pontiff are still related.]
Both are in Rome.
Cletus/Anacletus is shown in picture standing in/under an Arch. Titus is associated with the famous 'Arch of Titus'.
Cletus was a Roman (born Rome). Anacletus was a "Greek" ("place of birth Athens"). Titus was born in/at Rome. Titus' namesake in the bible was a Grecian and in Crete. (The name Titus might be related to Greek name Titan?) Titus "was a skilled poet and orator both in Greek and Latin".
Cletus/Anacletus: Shown in picture wearing a grand Crown/diadem, and wearing red/purple robe. Titus: Was emperor. "he was presented with a crown by Vologases I of Parthia." "the [Apis] ceremony required Titus to wear a diadem, which the Romans associated with monarchy".
Cletus/Anacletus: Was a "Saint". Has a halo/aura. Titus: Was deified.
With both the popes & emperors before & after also match all in order. 1 Peter (Nero) = Nero (Peter) 2 Linus = Vespasian 3 Cletus = Titus 4 Clement 1 = Domitian (Clemens) 5 Evaristus = Nerva 6 Alexander 1 = Trajan (Alexander) 7 Sixtus 1 = Trajan? or Hadrian? 8 Telesphorus = Hadrian? 9 Hyginus (Graecvs) = Hadrianus (Graeculus) 10 Pius 1 = Antoninus Pius etc. See each separate pope & emperor chapter for matches details.
There is no contemporary proof of existence of any pope Cletus/Anacletus. "Many popes in the first three centuries of the Christian era are obscure figures". Though Irenaeus mentioned Cletus in ca 180/195, and Augustine mentions Cletus in 411/415/416/422. Does Irenaeus say he was bishop? Even if he does, the date they first came up with the popes list is not certain, maybe they first came up with the pope/emperor correspondences even as early as Irenaeus? Cletus is omitted in some popes lists which have Clement directly after Peter.