Roman coin inscriptions contain numerous abbreviations which are rarely separated by punctuation marks. The following are amongst the commonest forms and collectors should try to familiarize themselves with these before attempting to transcribe legends.
AVG = Augustus, the honorific title bestowed on Octavian by the Senate on 16 January 27 BC and thereafter adopted by all of his successors as an indication of their supreme authority. [On some earlier coins of the Imperatorial period the abbreviation 'AVG' may be used to designate membership of the Augures, one of Rome's four principal priestly colleges].
C or CAES = Caesar, originally a cognomen of the Julia gens. In 49 BC Gaius Julius Caesar (later dictator) initiated the period of civil conflict which led to the downfall of the Republic and the establishment of autocratic rule under his heir, Octavian (Augustus). After the extinction of the Julio-Claudian dynasty Caesar was adopted as an imperial title by their successors. It was also borne by the heir to the throne prior to his assumption of supreme authority.
CONOB = Constantinopolis Obryza, 'Pure Gold of Constantinople'. This form of mint mark, appearing in the exergues of late Roman and Byzantine solidi and fractional gold denominations, had its origins in the second half of the 4th century. 'Obryza', a word of obscure derivation, indicated that the gold from which the coin had been struck had been tested and was guaranteed pure. Initially, other mints employed a similar formula (ANTOB for Antioch, MDOB for Mediolanum, etc.) but eventually CONOB came to be utilized universally, without regard to the actual place of mintage. An important variation appearing at a number of western mints was COMOB. This may have had a slightly different meaning, the COM possibly indicating the office of Comes Auri ('Count of Gold'), the official charged with the responsibility of supervising the Imperial gold supplies in the western provinces of the Empire.
COS = Consul, the highest annually elected magistracy of the Roman Republic. From 509 BC until the fall of the Republic two consuls were appointed each year to act as temporary heads of state. Consuls continued to hold office under the Imperial constitution and quite frequently the emperor himself, or his heir, occupied the position.
D N = Dominus Noster, 'Our Lord'. Introduced under the First Tetrarchy in the early years of the 4th century AD. Common after the middle of the century when it replaced IMP (erator) at the beginning of inscriptions.
DD NN = Dominorum Nostrorum, the plural of Dominus Noster.
III VIR/IIII VIR = Triumvir/Quattuorvir, 'One of Three/Four Men'. This title was used to describe the annual mint magistrates (usually three in number, but sometimes four) of the Republic and early Empire. This appointment formed an important step in the progression (cursus honorum) of a public career, possibly leading to an eventual consulate. The full title was Tres Viri/Quattuor Viri Aere Argento Auro Flando Feriundo ('Three/Four Men for the Casting [and] Striking of Bronze, Silver [and] Gold'). This sometimes appears on the coinage, notably the reformed aes denominations of Augustus where it is rendered as III VIR A A A F F.
III VIR R P C = Triumvir Reipublicae Constituendae, 'One of Three Men for the Regulation of the Republic'. The title adopted in November of 43 BC by the three Caesarian leaders (Mark Antony, Octavian and Lepidus) when they formed the Second Triumvirate to oppose the tyrannicides Brutus and Cassius.
IMP = Imperator, 'Commander'. Under the Republic it came to designate a victorious general whose success was enthusiastically acclaimed by his troops. In Imperial times it was often used to enumerate the victories of the emperor during the course of his reign, regardless of whether or not he was personally in command. The numbers of these acclamations are sometimes included in coin inscriptions (e.g. IMP II, IMP III, etc.).
PERP or PP = Perpetuus, 'Continuous'. In the early Empire this indicated the holding of a specific office for life, eg CENS(or) PERP(petuus) under Domitian. However, from the late 5th century into Byzantine times it replaced the traditional 'P F', standing on its own as an Imperial title immediately preceding that of Augustus.
P F = Pius Felix, 'Dutiful' (to the gods, the State, and to one's family) and 'Happy' (in good fortune and success). From the mid-3rd to the late 5th centuries AD these titles often immediately preceded that of Augustus, until superseded by 'PP' (Perpetuus).
P M = Pontifex Maximus, 'Greatest of the Pontifices'. The sixteen Pontifices formed one of the four senior colleges of priests in Rome and were charged with the supervision of ceremonies connected with the state religion. The head of the Pontifices was the Pontifex Maximus (a title still borne by the Pope today). Augustus received the title in 13 BC on the death of its last Republican holder, the former Triumvir Lepidus. Thereafter, it was normally assumed by each emperor at the time of his accession.
P P = Pater Patriae, 'Father of his Country'. Augustus received this title in 2 BC and it was subsequently adopted by most of his successors at the time of their accession. An earlier version (Parens Patriae) had been bestowed on Cicero after his exposure of the Catiline conspiracy in 63 BC and on Caesar in the final months of his life.
S C = Senatus Consulto, 'by Decree of the Senate'. Sometimes expressed more fully as EX S C. Referring to the authority by which the issue was made. Appears on most Imperial aes until the mid-3rd century, but also occasionally on precious metal issues of the Republic and early Empire.
S P Q R = Senatus Populusque Romanus, 'The Roman Senate and People'. The traditional formula expressing the joint authority of the conscript fathers and the common citizenry. Although having little meaning in Imperial times it continues to appear quite regularly on the coinage down to the time of Constantine the Great.
TR P = Tribunicia Potestas, 'Tribunician Power'. Established in the early days of the Republic, the office of Tribune of the Plebs ultimately carried with it wide ranging powers and protections, including inviolability of person. On 1 July 23 BC Augustus obtained a lifetime grant of the tribunician power, an important step in the establishment of an autocracy as it gave him the absolute right of veto as well as the authority to convene the Senate. The tribunician power was generally assumed at the commencement of each new reign, though some emperors had already received it during their predecessor's reign (eg Tiberius, Titus, Marcus Aurelius, etc.). It is of special interest when followed by a numeral as this allows a coin to be assigned to its precise year of issue, the tribunician power being renewed annually for the purpose of regnal dating.