Hi,
Ziegler,
Kaiser, Herr und städtisches Geld (also known as
Ziegler, Anazarbus), pg. 110, states that it means IEROS ISELASTIKOS and thus takes reference to the iselactic games, the Hadriania Olympia, occurring in Anazarbus. Iselastic means that victors
had the privilege of a triumphal entry into their
home cities.
Anazarbus was obviously proud of its right to have such high-level, iselastic games.
Hope this helps.
Best
Thilo