I am listing this as my cover of the day on the basis that I have not seen one of the cachets before, sometimes you don't notice these things until you take a close look.
So this is a WW1 Italian Red Cross stationary card used cancelled from ROMA 10 XII 1917 and posted to an Italian POW in Crossen (modern day in Western Poland) with the red machine Italian censor mark. On closer inspection under the machine Rome datestamp is the cachet Gepruft JGF vereid dolmetscher - translated 'sworn interpreter' - a cachet I can not recall having seen before.
Crossen was a large POW camp with prisoners from 'other ranks' from multiple countries, notably including Americans' Italians, British and Canadian. It was described by the Germans and a 'basic camp' I wonder how basic this could have been, given what we now know of POW camps in general.