This is about the use of APO postmarks used on letters mailed domestically. Someone asked about it in a different thread several months ago but I wasn't on StampoRama then.
They are quite rare but they do exist. I've checked over 1000 WWII APO covers recently and I found two.
The first one is from APO 26 while it was still in Ft Jackson, SC. That APO did not go overseas (in France) 7 Sept 1944. This cover is dated 7 Jun 44.


The second one is from APO 189 in Banning, California. This APO was not overseas during WWII.


Both have “ US Army Postal Service – A.P.O. “ without number cancels.

Terry


www.militaryphs.org/