Hi all, I'm seeking information relating to service records I recently obtained for my grandfather. He served two years (Nov 1942 to Dec 1944) as part of the Army of the United States and his discharge certificate is listed as "Battery A, 545th Field Artillery Battalion", but I can't find a single shred of information on this unit... not even what division it may have been attached to. From the looks of my limited research, this unit headed out to to the Pacific around ~1945 onboard the USS Millard County (LST-987), but this would've been well after my grandfather's service. I found a post on hree from a while back (by RichTO90) that describes how artillery battalions were "assigned" to various divisions, etc., so I'm hoping I may be able to get further info. In addition to the unit itself, I'm also interested in trying to clarify a few other items on his record: 1) His Army specialty is listed as "fireman". For this time frame, did this actually mean "firefighter" in the current day since, or - given the context of military service, did this mean "artilleryman"? (I've seen artillery units termed "fire" or "fires" etc.). 2) The "Remarks" section on the Enlisted Record of Service states: "(*) AR 615-365 % ar 13 SO 122 ASF 4th SerCom Hq Welch Conv Hosp, Daytona Beach, Fla., Dtd 25 Nov 44. No days lost under AW 107" I've been able to piece together that "AR 615-365" was the regulation that authorizes demobilization; and that "ASF 4th SerCom Hq" probably refers to the Army Service Forces 4th Service Command, which was HQ'd in Florida (per Wikipedia) and controlled the Florida-based hospital he was evaluated at and subsequently honorably discharged for medical reasons. This does line up with what my dad remembers (service in Florida before returning home to NYC; service in an artillery unit). What I can't figure out is not sure what the "ar 13 SO 122" means. (It also looks like there may be a missing character before the 'ar' but I can't figure that one out.) I've found that "SO" may mean Special Order, but there doesn't appear to be any standardization with these, and it all looks to be very localized... so i'm not sure what I can do about this. Thank you for your help!!