Acronyms from 1952 US Army document

Question

Seems the US Army in the 1950's was in love with acronyms even more than the 1975-1985 Navy I was in.

An excerpt from orders for my wife's late step-father:

15 Oct 1952
US Army Hospital 8079th AU
Special Orders #191
PFC (name) MOS 3060; EDDFEC Oct 52; 6-CMS; Det AMEDS 8079th Army Unit
Transfer to Camp Drake Replacement Depot for return to ZI for discharge
(16 Oct 1952)  PCS  TDN  TBGAA

The ones I don't know:  EDDFEC  CMS  AMEDS  ZI  PCS  TDN  TBGAA

When I was in the Navy, PCS was Permanent Change of Station, which seems weird when preparing for discharge.  TD was temporary duty, but TDN?

8079th was in Korea, in case it matters.

AMEDS might be Army Medical Service or Army Medical Department Center and School (where's the 'C'?) but he was a cook, not a medical service officer.  He could have been cooking at a hospital, or a patient, but I wouldn't have thought they'd have a school in Korea.

Answer 1

From quick googling, I found two sources from the WW2 and Korean War eras that match some of the abbreviations:

• this page with Korean war information suggests EDDFEC is "Estimated Date of Departure Far East Command", which matches the station in Korea and seems to be the time the person got orders to go back home

More potential hits from this WW2 era document:

• ZI: Zone of Interior (=outside combat zones)
• AMEDS: Army Medical Service
• PCS: Permanent Change of Station
• TDN: Travel directed is necessary in the military service
• TBGAA: Travel by government automobile authorized

I don't have a military background or enough knowledge of Army procedures to interpret this, but my first guess would be that the "simple" process of discharging the person consisted of different formal steps (including the PCS) and some "vouchers" (in an abstract sense) for transportation to actually get the person somewhere.