Another reference gives this explanation (translated from old
French):
« We can hardly doubt, he says, that the letter I, 10, has a direct relationship with the
head in front of which it is placed, and indicates the tenth solemnity celebrated by the Alpendians, in
honor of
Salonina, and that the letter ©, 5, only expresses that this tenth solemnity is the fifth that they celebrated at the temple of Themis. »
DT
https://books.google.ca/books?id=unwGAAAAQAAJ&pg=PA59&lpg=PA59&dq=