Forms of verbal address between officers and soldiers.

[Tarbicus]

(although, even as an officer, I would have hardly tried to treat a RSM - probably the closest modern equivalent to a primus pilus -

Just a really quick note on that, and might tell us why we can't seem to agree on this :wink: A primus pilus was more akin to a colonel IMO and IIRC. The idea of centurions being NCOs is a red herring.

Sicily has been exposed to other patronus-client (or grandee-commoner) relationships during the Arab, Norman, French, Aragonese and Spanish dominations

Aside from Arabic and Norman, weren't the others of directly Roman cultural heritage in the 9th-C anyway? If the Norman conquerors of Britain are anything to go by, would they be changing much of society's fabric or language during their stay? There is a suggestion out there that the word mafia has its roots in Arabic:
"Another theory of the origin of "mafia" begins as early as the 9th century. During that period, Sicily was ruled by Arab forces. The original inhabitants were oppressed, and desperately tried to escape and find refuge. In Arabic, the word "mafia" means, "refuge." Sicily was invaded by the Normans in the 11th century and its people were forced into labor and oppression once again. Every invasion of Sicily, thereafter, (French invasion in the 12th century, Spanish in the 13th century, then Germans, Austrians, and Greeks) resulted in native tribes seeking refuge in the hills of the island. The refugees eventually developed a secret society of unification intended to create a sense of family, based on Sicilian heritage. The structure of the organization was built on the idea of family and had a strong hierarchical make up. The "dons" were the family heads, in charge of the mafia in every village. They had to report to the "don of dons", who lived in Palermo, the capital of Sicily."
http://da_wizeguy.tripod.com/omerta/id1.html
But I'd be remiss not to point out this: http://www.sicilianculture.com/mafia/mafiawords.htm