A.m.g Sicily Cover, Assistance Needed

I've got this A.M.G. cover, and the large A.C.S that is stamped twice diagonally confuses me.



What I can gather so far about this cover is:
it is from the Psychiatric Hospital of Pallermo.
it is to the president of the provisional administration
it is sent 5/20/1944

(ive opened it up and saw it was a letter of discharge for a patient and the arrival postmark was 5/23/44 in Trapani)

A.C.S kind of looks like the same color ink as the Hospedale Psichiatrico el Pallermo stamp so I'm wondering if A.C.S might be an italian medical acronym. I'm just guessing though, any help is appreciated.

Allied Control System ?
https://www.academiedephilatelie.fr...jeg_1509.pdf

Hello,

From the Postal Manual written by the Civil Censorship Group Italy(1944) and published by the Military Postal History Society(USA):
"to denote that a piece of correspondence has passed through a Civil Censorship Group provincial censorship station but has not been opened and examined, the following stamp will be used:ACS"

https://forum.aicpm.net/viewtopic.php?f=28&t=151

The ACS stamp usually was applied at departure or in transit.

There were different shapes of ACS(Sicily):



https://www.ilpostalista.it/sirotti/sirotti02.htm

As far as I know the meaning of ACS could be either "Allied Censorship Station " or "Allied Censorship Service"

@alka2 thank you for this information! This is super helpful!