In
Roman Imperial Coinage VII, there is reference to a campgate from Arles issued for Constantius II with a Greek letter for the officina. The problem is that Arles used Latin letters for all its other campgates (P, S, T, Q)
In the footnotes Bruun first talks about two coins in Vienna with the mintmark ARL∆ with no field marks and then talks about an example with the fieldmarks S/F -
"the latter on the evidence of a coin the existence of which the present writer has not been able to verify, illustrated by a drawing in Voetter's Appendix, NZ 1909, pl. 13 (off. ∆). The author prefers to regard these mint-marks, or this way of marking the fourth officina, as a peculiar slip of some mint official and not as indicative of an issue marking the officinae with Greek letters." RIC VII pg 268 footnote 312
Bruun had a habit of dismissing coins as a "peculiar slip" if they did not fit in nicely to his narrative. However, more and more examples of campgates from Arles with Greek workshops have turned up in recent years. With this many coins, it does not seem conceivable that it is merely a "slip"
These are all without the S/F in the fields, though. Maybe there are examples with S/F out there also, except that nobody has noticed them. Depeyrot mentions the two examples from Vienna, talked about by Bruun, and wonders if they are imitations (
Les Admissions monetaires d'Arles pg 59). Ferrando in
L'atelier monetaire d'Arles lists the ARLA series without field marks, but does not have any S/F examples listed. Guido Bruck, who used the Vienna collection for his book
Die Spatromische Kupferpragung, avoided the whole issue by not worrying about workshops, only writing the mintmark as ARL.
So pay attention to the Arles campgates, especially the ones with S/F and maybe you will find Voetter's lost issue.
The first picture is from Otto Voetter "Constantinvs Junior als Augustus" 1909
The coin pictures are from Lech's Not in RIC site
